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Lingua::EN::Inflect(3)User Contributed Perl DocumentatioLingua::EN::Inflect(3)

       Lingua::EN::Inflect - Convert singular to plural. Select	"a" or "an".

       This document describes version 1.905 of	Lingua::EN::Inflect

	use Lingua::EN::Inflect	qw ( PL	PL_N PL_V PL_ADJ NO NUM
			 PL_eq PL_N_eq PL_V_eq PL_ADJ_eq
			 A AN
			 inflect classical
			 def_noun def_verb def_adj def_a def_an	);


	     print "The	plural of ", $word, " is ", PL($word), "\n";


	     print "I saw $cat_count ",	PL("cat",$cat_count), "\n";


	     print PL_N("I",$N1), PL_V("saw",$N1),
	       PL_ADJ("my",$N2), PL_N("saw",$N2), "\n";

	# DEAL WITH "0/1/N" -> "no/1/N"	TRANSLATION:

	     print "There ", PL_V("was",$errors), NO(" error",$errors),	"\n";


	     print NUM($N1,""),	PL("I"), PL_V("	saw"), NUM($N2), PL_N("	saw");
	     print "There ", NUM($errors,''), PL_V("was"), NO("	error"), "\n";


	     print "same\n"	 if PL_eq($word1, $word2);
	     print "same noun\n" if PL_N_eq($word1, $word2);
	     print "same verb\n" if PL_V_eq($word1, $word2);
	     print "same adj.\n" if PL_ADJ_eq($word1, $word2);


	     print "Did	you want ", A($thing), " or ", AN($idea), "\n";

	# CONVERT NUMERALS INTO	ORDINALS (i.e. 1->1st, 2->2nd, 3->3rd, etc.)

	     print "It was", ORD($position), " from the	left\n";

	# CONVERT NUMERALS TO WORDS (i.e. 1->"one", 101->"one hundred and one",	etc.)

	   $words = NUMWORDS(1234);	 # "one	thousand, two hundred and thirty-four"
	   $words = NUMWORDS(ORD(1234)); # "one	thousand, two hundred and thirty-fourth"


	   @words = NUMWORDS(1234);    # ("one thousand","two hundred and thirty-four")


	   $words = NUMWORDS(12345, group=>1);
		       # "one, two, three, four, five"

	   $words = NUMWORDS(12345, group=>2);
		       # "twelve, thirty-four, five"

	   $words = NUMWORDS(12345, group=>3);
		       # "one twenty-three, forty-five"

	   $words = NUMWORDS(1234, 'and'=>'');
		       # "one thousand,	two hundred thirty-four"

	   $words = NUMWORDS(1234, 'and'=>', plus');
		       # "one thousand,	two hundred, plus thirty-four"

	   $words = NUMWORDS(555_1202, group=>1, zero=>'oh');
		       # "five,	five, five, one, two, oh, two"

	   $words = NUMWORDS(555_1202, group=>1, one=>'unity');
		       # "five,	five, five, unity, two,	zero, two"

	   $words = NUMWORDS(123.456, group=>1,	decimal=>'mark');
		       # "one two three	mark four five six"


	   $words = NUMWORDS(	9, threshold=>10);    #	"nine"
	   $words = NUMWORDS(  10, threshold=>10);    #	"ten"
	   $words = NUMWORDS(  11, threshold=>10);    #	"11"
	   $words = NUMWORDS(1000, threshold=>10);    #	"1,000"


	   $list = WORDLIST("apple", "banana", "carrot");
		       # "apple, banana, and carrot"

	   $list = WORDLIST("apple", "banana");
		       # "apple	and banana"

	   $list = WORDLIST("apple", "banana", "carrot", {final_sep=>""});
		       # "apple, banana	and carrot"

	# REQUIRE "CLASSICAL" PLURALS (EG: "focus"->"foci", "cherub"->"cherubim")

	     classical;		 # USE ALL CLASSICAL PLURALS

	     classical 1;	    #  USE ALL CLASSICAL PLURALS
	     classical 0;	    #  USE ALL MODERN PLURALS (DEFAULT)

	     classical 'zero';	    #  "no error" INSTEAD OF "no errors"
	     classical zero=>1;	    #  "no error" INSTEAD OF "no errors"
	     classical zero=>0;	    #  "no errors" INSTEAD OF "no error"

	     classical 'herd';	    #  "2 buffalo" INSTEAD OF "2 buffalos"
	     classical herd=>1;	    #  "2 buffalo" INSTEAD OF "2 buffalos"
	     classical herd=>0;	    #  "2 buffalos" INSTEAD OF "2 buffalo"

	     classical 'persons';   # "2 chairpersons" INSTEAD OF "2 chairpeople"
	     classical persons=>1;  # "2 chairpersons" INSTEAD OF "2 chairpeople"
	     classical persons=>0;  # "2 chairpeople" INSTEAD OF "2 chairpersons"

	     classical 'ancient';   # "2 formulae" INSTEAD OF "2 formulas"
	     classical ancient=>1;  # "2 formulae" INSTEAD OF "2 formulas"
	     classical ancient=>0;  # "2 formulas" INSTEAD OF "2 formulae"

	# INTERPOLATE "PL()", "PL_N()",	"PL_V()", "PL_ADJ()", A()", "AN()"

	     print inflect("The	plural of $word	is PL($word)\n");
	     print inflect("I saw $cat_count PL(cat,$cat_count)\n");
	     print inflect("PL(I,$N1) PL_V(saw,$N1) PL(a,$N2) PL_N(saw,$N2)\n");
	     print inflect("NUM($N1,)PL(I) PL_V(saw) NUM($N2,)PL(a) PL_N(saw)\n");
	     print inflect("I saw NUM($cat_count) PL(cat)\n");
	     print inflect("There PL_V(was,$errors) NO(error,$errors)\n");
	     print inflect("There NUM($errors,)PL_V(was) NO(error)\n");
	     print inflect("Did	you want A($thing) or AN($idea)\n");
	     print inflect("It was ORD($position) from the left\n");


	     def_noun  "VAX"  => "VAXen";  # SINGULAR => PLURAL

	     def_verb  "will" => "shall",  # 1ST PERSON	SINGULAR => PLURAL
		       "will" => "will",   # 2ND PERSON	SINGULAR => PLURAL
		       "will" => "will";   # 3RD PERSON	SINGULAR => PLURAL

	     def_adj   "hir"  => "their";  # SINGULAR => PLURAL

	     def_a     "h";		   # "AY HALWAYS SEZ 'HAITCH'!"

	     def_an    "horrendous.*";	   # "AN HORRENDOUS AFFECTATION"

       [Note: This module is strictly in maintenance mode now.	Take a look at
       the newer Lingua::EN::Inflexion module, which offers a cleaner and more
       convenient interface, has many more features (including
       plural->singular	inflexions), and is also much better tested.  If you
       have existing code that relies on Lingua::EN::Inflect, see the section
       of the documentation entitled "CONVERTING FROM LINGUA::EN::INFLECT". ]

       The exportable subroutines of Lingua::EN::Inflect provide plural
       inflections, "a"/"an" selection for English words, and manipulation of
       numbers as words

       Plural forms of all nouns, most verbs, and some adjectives are
       provided. Where appropriate, "classical"	variants (for example:
       "brother" -> "brethren",	"dogma"	-> "dogmata", etc.) are	also provided.

       Pronunciation-based "a"/"an" selection is provided for all English
       words, and most initialisms.

       It is also possible to inflect numerals (1,2,3) to ordinals (1st, 2nd,
       3rd) and	to English words ("one", "two",	"three).

       In generating these inflections,	Lingua::EN::Inflect follows the	Oxford
       English Dictionary and the guidelines in	Fowler's Modern	English	Usage,
       preferring the former where the two disagree.

       The module is built around standard British spelling, but is designed
       to cope with common American variants as	well. Slang, jargon, and other
       English dialects	are not	explicitly catered for.

       Where two or more inflected forms exist for a single word (typically a
       "classical" form	and a "modern" form), Lingua::EN::Inflect prefers the
       more common form	(typically the "modern"	one), unless "classical"
       processing has been specified (see "MODERN VS CLASSICAL INFLECTIONS").

   Inflecting Plurals
       All of the "PL_..." plural inflection subroutines take the word to be
       inflected as their first	argument and return the	corresponding
       inflection.  Note that all such subroutines expect the singular form of
       the word. The results of	passing	a plural form are undefined (and
       unlikely	to be correct).

       The "PL_..." subroutines	also take an optional second argument, which
       indicates the grammatical "number" of the word (or of another word with
       which the word being inflected must agree). If the "number" argument is
       supplied	and is not 1 (or "one" or "a", or some other adjective that
       implies the singular), the plural form of the word is returned. If the
       "number"	argument does indicate singularity, the	(uninflected) word
       itself is returned. If the number argument is omitted, the plural form
       is returned unconditionally.

       The various subroutines are:

	       The exportable subroutine "PL_N()" takes	a singular English
	       noun or pronoun and returns its plural. Pronouns	in the
	       nominative ("I" -> "we")	and accusative ("me" ->	"us") cases
	       are handled, as are possessive pronouns ("mine" -> "ours").

	       The exportable subroutine "PL_V()" takes	the singular form of a
	       conjugated verb (that is, one which is already in the correct
	       "person"	and "mood") and	returns	the corresponding plural

	       The exportable subroutine "PL_ADJ()" takes the singular form of
	       certain types of	adjectives and returns the corresponding
	       plural form.  Adjectives	that are correctly handled include:
	       "numerical" adjectives ("a" -> "some"), demonstrative
	       adjectives ("this" -> "these", "that" ->	"those"), and
	       possessives ("my" -> "our", "cat's" -> "cats'", "child's" ->
	       "childrens'", etc.)

	       The exportable subroutine "PL()"	takes a	singular English noun,
	       pronoun,	verb, or adjective and returns its plural form.	Where
	       a word has more than one	inflection depending on	its part of
	       speech (for example, the	noun "thought" inflects	to "thoughts",
	       the verb	"thought" to "thought"), the (singular)	noun sense is
	       preferred to the	(singular) verb	sense.

	       Hence "PL("knife")" will	return "knives"	("knife" having	been
	       treated as a singular noun), whereas "PL("knifes")" will	return
	       "knife" ("knifes" having	been treated as	a 3rd person singular

	       The inherent ambiguity of such cases suggests that, where the
	       part of speech is known,	"PL_N",	"PL_V",	and "PL_ADJ" should be
	       used in preference to "PL".

       Note that all these subroutines ignore any whitespace surrounding the
       word being inflected, but preserve that whitespace when the result is
       returned. For example, "PL("A catA A ")"	returns	"A catsA A ".

   Numbered plurals
       The "PL_..." subroutines	return only the	inflected word,	not the	count
       that was	used to	inflect	it. Thus, in order to produce "I saw 3 ducks",
       it is necessary to use:

	   print "I saw	$N ", PL_N($animal,$N),	"\n";

       Since the usual purpose of producing a plural is	to make	it agree with
       a preceding count, Lingua::EN::Inflect provides an exportable
       subroutine ("NO($;$)") which, given a word and a(n optional) count,
       returns the count followed by the correctly inflected word. Hence the
       previous	example	can be rewritten:

	   print "I saw	", NO($animal,$N), "\n";

       In addition, if the count is zero (or some other	term which implies
       zero, such as "zero", "nil", etc.) the count is replaced	by the word
       "no". Hence, if $N had the value	zero, the previous example would print
       the somewhat more elegant:

	   I saw no animals

       rather than:

	   I saw 0 animals

       Note that the name of the subroutine is a pun: the subroutine returns
       either a	number (a No.) or a "no", in front of the inflected word.

       Wordy and comma'd plurals

       The "NO()" subroutine takes an optional third argument: a hash of named
       options that configure its behaviour.

       The 'words_below' option	informs	"NO()" what other numbers (i.e.	 apart
       from zero) it should convert to words. For example:S

	   for my $count (0..12) {
	       print NO('cat', $count, {words_below => 10}), "\n";

       would print:

	   no cats
	   one cat
	   two cats
	   three cats
	   four	cats
	   five	cats
	   six cats
	   seven cats
	   eight cats
	   nine	cats
	   10 cats
	   11 cats
	   12 cats

       The 'comma' and 'comma_every' options determine whether or not the
       numbers produced	by "NO()" have commas in them. That is:

	   2001	space odysseys


	   2,001 space odysseys

       Normally, numbers are produced without commas, but if 'comma' or
       'comma_every' is	specified, then	commas are added as requested.

       The 'comma' option specifies which character to use as a	comma.	It
       defaults	to ',',	but may	be set to anything convenient:

	   print NO('Euro', $amount, {comma=>'.'});

	   # prints:  1.000.000	Euros

       The 'comma_every' option	specifies how many characters between commas.
       It defaults to 3, but may be set	to any positive	number:

	   print NO('Euro', $amount, {comma_every=>4});

	   # prints:  100,0000 Euros

       Note that you can set both options at once, if you wish:

	   print NO('Euro', $amount, {comma_every=>2, comma=>'_'});

	   # prints:  1_00_00_00 Euros

   Reducing the	number of counts required
       In some contexts, the need to supply an explicit	count to the various
       "PL_..."	subroutines makes for tiresome repetition. For example:

	   print PL_ADJ("This",$errors), PL_N("	error",$errors),
		 PL_V("	was",$errors), " fatal.\n";

       Lingua::EN::Inflect therefore provides an exportable subroutine
       ("NUM($;$)") that may be	used to	set a persistent "default number"
       value. If such a	value is set, it is subsequently used whenever an
       optional	second "number"	argument is omitted. The default value thus
       set can subsequently be removed by calling "NUM()" with no arguments.
       Hence we	could rewrite the previous example:

	   print PL_ADJ("This"), PL_N("	error"), PL_V("	was"), "fatal.\n";

       Normally, "NUM()" returns its first argument, so	that it	may also be
       "inlined" in contexts like:

	   print NUM($errors), PL_N(" error"), PL_V(" was"), " detected.\n"
	   print PL_ADJ("This"), PL_N("	error"), PL_V("	was"), "fatal.\n"
	       if $severity > 1;

       However,	in certain contexts (see "INTERPOLATING	INFLECTIONS IN
       STRINGS") it is preferable that "NUM()" return an empty string. Hence
       "NUM()" provides	an optional second argument. If	that argument is
       supplied	(that is, if it	is defined) and	evaluates to false, "NUM"
       returns an empty	string instead of its first argument. For example:

	   print NUM($errors,0), NO("error"), PL_V(" was"), " detected.\n";
	   print PL_ADJ("This"), PL_N("	error"), PL_V("	was"), "fatal.\n"
	       if $severity > 1;

   Number-insensitive equality
       Lingua::EN::Inflect also	provides a solution to the problem of
       comparing words of differing plurality through the exportable
       subroutines "PL_eq($$)",	"PL_N_eq($$)", "PL_V_eq($$)", and
       "PL_ADJ_eq($$)".	 Each  of these	subroutines takes two strings, and
       compares	them using the corresponding plural-inflection subroutine
       ("PL()",	"PL_N()", "PL_V()", and	"PL_ADJ()" respectively).

       The comparison returns true if:

       o       the strings are "eq"-equal, or

       o       one string is "eq"-equal	to a plural form of the	other, or

       o       the strings are two different plural forms of the one word.

       Hence all of the	following return true:

	   PL_eq("index","index")      # RETURNS "eq"
	   PL_eq("index","indexes")    # RETURNS "s:p"
	   PL_eq("index","indices")    # RETURNS "s:p"
	   PL_eq("indexes","index")    # RETURNS "p:s"
	   PL_eq("indices","index")    # RETURNS "p:s"
	   PL_eq("indices","indexes")  # RETURNS "p:p"
	   PL_eq("indexes","indices")  # RETURNS "p:p"
	   PL_eq("indices","indices")  # RETURNS "eq"

       As indicated by the comments in the previous example, the actual	value
       returned	by the various "PL_eq" subroutines encodes which of the	three
       equality	rules succeeded: "eq" is returned if the strings were
       identical, "s:p"	if the strings were singular and plural	respectively,
       "p:s" for plural	and singular, and "p:p"	for two	distinct plurals.
       Inequality is indicated by returning an empty string.

       It should be noted that two distinct singular words which happen	to
       take the	same plural form are not considered equal, nor are cases where
       one (singular) word's plural is the other (plural) word's singular.
       Hence all of the	following return false:

	   PL_eq("base","basis")       # ALTHOUGH BOTH -> "bases"
	   PL_eq("syrinx","syringe")   # ALTHOUGH BOTH -> "syringes"
	   PL_eq("she","he")	   # ALTHOUGH BOTH -> "they"

	   PL_eq("opus","operas")      # ALTHOUGH "opus" -> "opera" -> "operas"
	   PL_eq("taxi","taxes")       # ALTHOUGH "taxi" -> "taxis" -> "taxes"

       Note too	that, although the comparison is "number-insensitive" it is
       not case-insensitive (that is, "PL("time","Times")" returns false. To
       obtain both number and case insensitivity, prefix both arguments	with
       "lc" (that is, "PL(lc "time", lc	"Times")" returns true).

   Present participles
       "Lingua::EN::Inflect" also provides the "PART_PRES" subroutine, which
       can take	a 3rd person singular verb and correctly inflect it to its
       present participle:

	   PART_PRES("runs")   # "running"
	   PART_PRES("loves")  # "loving"
	   PART_PRES("eats")   # "eating"
	   PART_PRES("bats")   # "batting"
	   PART_PRES("spies")  # "spying"

   Selecting indefinite	articles
       Lingua::EN::Inflect provides two	exportable subroutines ("A($;$)" and
       "AN($;$)") which	will correctly prepend the appropriate indefinite
       article to a word, depending on its pronunciation. For example:

	   A("cat")	   # ->	"a cat"
	   AN("cat")	   # ->	"a cat"
	   A("euphemism")      # -> "a euphemism"
	   A("Euler number")   # -> "an	Euler number"
	   A("hour")	   # ->	"an hour"
	   A("houri")	   # ->	"a houri"

       The two subroutines are identical in function and may be	used
       interchangeably.	The only reason	that two versions are provided is to
       enhance the readability of code such as:

	   print "That is ", AN($errortype), " error\n;
	   print "That is ", A($fataltype), " fatal error\n;

       Note that in both cases the actual article provided depends only	on the
       pronunciation of	the first argument, not	on the name of the subroutine.

       "A()" and "AN()"	will ignore any	indefinite article that	already	exists
       at the start of the string. Thus:

	   @half_arked = (
	       "a elephant",
	       "a giraffe",
	       "an ewe",
	       "a orangutan",

	   print A($_),	"\n" for @half_arked;

	   # prints:
	   #	 an elephant
	   #	 a giraffe
	   #	 a ewe
	   #	 an orangutan

       "A()" and "AN()"	both take an optional second argument. As with the
       "PL_..."	subroutines, this second argument is a "number"	specifier. If
       its value is 1 (or some other value implying singularity), "A()"	and
       "AN()" insert "a" or "an" as appropriate. If the	number specifier
       implies plurality, ("A()" and "AN()" insert the actual second argument
       instead.	 For example:

	   A("cat",1)	   # ->	"a cat"
	   A("cat",2)	   # ->	"2 cat"
	   A("cat","one")      # -> "one cat"
	   A("cat","no")       # -> "no	cat"

       Note that, as implied by	the previous examples, "A()" and "AN()"	both
       assume that their job is	merely to provide the correct qualifier	for a
       word (that is: "a", "an", or the	specified count).  In other words,
       they assume that	the word they are given	has already been correctly
       inflected for plurality.	Hence, if $N has the value 2, then:

	     print A("cat",$N);

       prints "2 cat", instead of "2 cats". The	correct	approach is to use:

	     print A(PL("cat",$N),$N);

       or, better still:

	     print NO("cat",$N);

       Note too	that, like the various "PL_..."	subroutines, whenever "A()"
       and "AN()" are called with only one argument they are subject to	the
       effects of any preceding	call to	"NUM()". Hence,	another	possible
       solution	is:

	     print A(PL("cat"));

   Indefinite articles and initialisms
       "Initialisms" (sometimes	inaccurately called "acronyms")	are terms
       which have been formed from the initial letters of words	in a phrase
       (for example, "NATO", "NBL", "S.O.S.", "SCUBA", etc.)

       Such terms present a particular challenge when selecting	between	"a"
       and "an", since they are	sometimes pronounced as	if they	were a single
       word ("nay-tow",	"sku-ba") and sometimes	as a series of letter names
       ("en-eff-ell", "ess-oh-ess").

       "A()" and "AN()"	cope with this dichotomy using a series	of inbuilt
       rules, which may	be summarized as:

       1.      If the word starts with a single	letter,	followed by a period
	       or dash (for example, "R.I.P.", "C.O.D.", "e-mail", "X-ray",
	       "T-square"), then choose	the appropriate	article	for the	sound
	       of the first letter ("an	R.I.P.", "a C.O.D.", "an e-mail", "an
	       X-ray", "a T-square").

       2.      If the first two	letters	of the word are	capitals, consonants,
	       and do not appear at the	start of any known English word, (for
	       example,	"LCD", "XML", "YWCA"), then once again choose "a" or
	       "an" depending on the sound of the first	letter ("an LCD", "an
	       XML", "a	YWCA").

       3.      Otherwise, assume the string is a capitalized word or a
	       pronounceable initialism	(for example, "LED", "OPEC", "FAQ",
	       "UNESCO"), and therefore	takes "a" or "an" according to the
	       (apparent) pronunciation	of the entire word ("a LED", "an
	       OPEC", "a FAQ", "a UNESCO").

       Note that rules 1 and 3 together	imply that the presence	or absence of
       punctuation may change the selection of indefinite article for a
       particular initialism (for example, "a FAQ" but "an F.A.Q.").

   Indefinite articles and "soft H's"
       Words beginning in the letter 'H' present another type of difficulty
       when selecting a	suitable indefinite article. In	a few such words (for
       example,	"hour",	"honour", "heir") the 'H' is not voiced	at all,	and so
       such words inflect with "an". The remaining cases ("voiced H's")	may be
       divided into two	categories: "hard H's" (such as	"hangman",
       "holograph", "hat", etc.) and "soft H's"	(such as "hysterical",
       "horrendous", "holy", etc.)

       Hard H's	always take "a"	as their indefinite article, and soft H's
       normally	do so as well. But some	English	speakers prefer	"an" for soft
       H's (although the practice is now generally considered an affectation,
       rather than a legitimate	grammatical alternative).

       At present, the "A()" and "AN()"	subroutines ignore soft	H's and	use
       "a" for any voiced 'H'. The author would, however, welcome feedback on
       this decision (envisaging a possible future "soft H" mode).

       Occasionally it is useful to present an integer value as	an ordinal
       rather than as a	numeral. For example:

	   Enter password (1st attempt): ********
	   Enter password (2nd attempt): *********
	   Enter password (3rd attempt): *********
	   No 4th attempt. Access denied.

       To this end, Lingua::EN::Inflect	provides the "ORD()" subroutine.
       <ORD()> takes a single argument and forms its ordinal equivalent.  If
       the argument isn't a numerical integer, it just adds "-th".

       The exportable subroutine "NUMWORDS" takes a number (cardinal or
       ordinal)	and returns an English representation of that number. In a
       scalar context a	string is returned. Hence:

	   use Lingua::EN::Inflect qw( NUMWORDS	);

	   $words = NUMWORDS(1234567);

       puts the	string:

	   "one	million, two hundred and thirty-four thousand, five hundred and	sixty-seven"

       into $words.

       In a list context each comma-separated chunk is returned	as a separate
       element.	 Hence:

	   @words = NUMWORDS(1234567);

       puts the	list:

	   ("one million",
	    "two hundred and thirty-four thousand",
	    "five hundred and sixty-seven")

       into @words.

       Note that this also means that:

	   print NUMWORDS(1234567);

       will (misprint) print:

	   one milliontwo hundred and thirty-four thousandfive hundred and sixty-seven

       To get readable output, make sure the call in in	scalar context:

	   print scalar	NUMWORDS(1234567);

       Non-digits (apart from an optional leading plus or minus	sign, any
       decimal points, and ordinal suffixes -- see below) are silently
       ignored,	so the following all produce identical results:


       That last case is a little awkward since	it's almost certainly a	phone
       number, and "five million, five hundred and fifty-one thousand, two
       hundred and two"	probably isn't what's wanted.

       To overcome this, "NUMWORDS()" takes an optional	named argument,
       'group',	which changes how numbers are translated. The argument must be
       a positive integer less than four, which	indicated how the digits of
       the number are to be grouped. If	the argument is	1, then	each digit is
       translated separately. If the argument is 2, pairs of digits (starting
       from the	left) are grouped together. If the argument is 3, triples of
       numbers (again, from the	left) are grouped. Hence:

	       NUMWORDS("555-1202", group=>1)

       returns "five, five, five, one, two, zero, two",	whilst:

	       NUMWORDS("555-1202", group=>2)

       returns "fifty-five, fifty-one, twenty, two", and:

	       NUMWORDS("555-1202", group=>3)

       returns "five fifty-five, one twenty, two".

       Phone numbers are often written in words	as
       "",	which is also easy to achieve:

	       join '..', NUMWORDS("555-1202", group=>1)

       "NUMWORDS" also handles decimal fractions. Hence:


       returns "one point two three four five" in a scalar context and
       "("one","point","two","three","four","five")") in an array context.
       Exponent	form ("1.234e56") is not yet handled.

       Multiple	decimal	points are only	translated in one of the "grouping"
       modes.  Hence:


       returns "one hundred and	one point two zero two three zero three",

	       NUMWORDS(101.202.303, group=>1)

       returns "one zero one point two zero two	point three zero three".

       The digit '0' is	unusual	in that	in may be translated to	English	as
       "zero", "oh", or	"nought". To cater for this diversity, "NUMWORDS" may
       be passed a named argument, 'zero', which may be	set to the desired
       translation of '0'. For example:

	       print join "..",	NUMWORDS("555-1202", group=>3, zero=>'oh')

       prints "".  By default, zero is
       rendered	as "zero".

       Likewise, the digit '1' may be rendered as "one"	or "a/an" (or very
       occasionally other variants), depending on the context. So there	is a
       'one' argument as well:

	       print NUMWORDS($_, one=>'a solitary', zero=>'no more'),
		     PL(" bottle of beer on the	wall\n", $_)
			  for (3,2,1,0);

	       # prints:
	       #     three bottles of beer on the wall
	       #     two bottles of beer on the	wall
	       #     a solitary	bottle of beer on the wall
	       #     no	more bottles of	beer on	the wall

       Care is needed if the word "a/an" is to be used as a 'one' value.
       Unless the next word is known in	advance, it's almost always necessary
       to use the "A" function as well:

	       print A(	NUMWORDS(1, one=>'a') .	" $_\n")
		for qw(cat aardvark ewe	hour);

	   # prints:
	   #	 a cat
	   #	 an aardvark
	   #	 a ewe
	   #	 an hour

       Another major regional variation	in number translation is the use of
       "and" in	certain	contexts. The named argument 'and' allows the
       programmer to specify how "and" should be handled. Hence:

	       print scalar NUMWORDS("765", 'and'=>'')

       prints "seven hundred sixty-five", instead of "seven hundred and	sixty-
       five".  By default, the "and" is	included.

       The translation of the decimal point is also subject to variation (with
       "point",	"dot", and "decimal" being the favorites).  The	named argument
       'decimal' allows	the programmer to how the decimal point	should be
       rendered. Hence:

	       print scalar NUMWORDS("666.124.64.101", group=>3, decimal=>'dot')

       prints "six sixty-six, dot, one twenty-four, dot, sixty-four, dot, one
       zero one" By default, the decimal point is rendered as "point".

       "NUMWORDS" also handles the ordinal forms of numbers. So:

	       print scalar NUMWORDS('1st');
	       print scalar NUMWORDS('3rd');
	       print scalar NUMWORDS('202nd');
	       print scalar NUMWORDS('1000000th');


	       two hundred and twenty-second
	       one millionth

       Two common idioms in this regard	are:

	       print scalar NUMWORDS(ORD($number));


	       print scalar ORD(NUMWORDS($number));

       These are identical in effect, except when $number contains a decimal:

	       $number = 99.09;
	       print scalar NUMWORDS(ORD($number));    # ninety-ninth point zero nine
	       print scalar ORD(NUMWORDS($number));    # ninety-nine point zero	ninth

       Use whichever you feel is most appropriate.

       When creating a list of words, commas are used between adjacent items,
       except if the items contain commas, in which case semicolons are	used.
       But if there are	less than two items, the commas/semicolons are omitted
       entirely. The final item	also has a conjunction (usually	"and" or "or")
       before it. And although it's technically	incorrect (and sometimes
       misleading), some people	prefer to omit the comma before	that final
       conjunction, even when there are	more than two items.

       That's complicated enough to warrant its	own subroutine:	"WORDLIST()".
       This subroutine expects a list of words,	possibly with one or more hash
       references containing options. It returns a string that joins the list
       together	in the normal English usage. For example:

	   print "You chose ", WORDLIST(@selected_items), "\n";
	   # You chose barley soup, roast beef,	and Yorkshire pudding

	   print "You chose ", WORDLIST(@selected_items, {final_sep=>""}), "\n";
	   # You chose barley soup, roast beef and Yorkshire pudding

	   print "Please chose ", WORDLIST(@side_orders, {conj=>"or"}),	"\n";
	   # Please chose salad, vegetables, or	ice-cream

       The available options are:

	   Option named	   Specifies		    Default value

	   conj		   Final conjunction	    "and"
	   sep		   Inter-item separator	    ","
	   last_sep	   Final separator	    value of 'sep' option

       By far the commonest use	of the inflection subroutines is to produce
       message strings for various purposes. For example:

	       print NUM($errors), PL_N(" error"), PL_V(" was"), " detected.\n";
	       print PL_ADJ("This"), PL_N(" error"), PL_V(" was"), "fatal.\n"
		       if $severity > 1;

       Unfortunately the need to separate each subroutine call detracts
       significantly from the readability of the resulting code. To ameliorate
       this problem, Lingua::EN::Inflect provides an exportable	string-
       interpolating subroutine	(inflect($)), which recognizes calls to	the
       various inflection subroutines within a string and interpolates them

       Using "inflect" the previous example could be rewritten:

	       print inflect "NUM($errors) PL_N(error) PL_V(was) detected.\n";
	       print inflect "PL_ADJ(This) PL_N(error) PL_V(was) fatal.\n"
		       if $severity > 1;

       Note that "inflect" also	correctly handles calls	to the "NUM()"
       subroutine (whether interpolated	or antecedent).	The "inflect()"
       subroutine has a	related	extra feature, in that it automatically
       cancels any "default number" value before it returns its	interpolated
       string. This means that calls to	"NUM()"	which are embedded in an
       "inflect()"-interpolated	string do not "escape" and interfere with
       subsequent inflections.

       Certain words, mainly of	Latin or Ancient Greek origin, can form
       plurals either using the	standard English "-s" suffix, or with their
       original	Latin or Greek inflections. For	example:

	       PL("stigma")	       # -> "stigmas" or "stigmata"
	       PL("torus")	       # -> "toruses" or "tori"
	       PL("index")	       # -> "indexes" or "indices"
	       PL("millennium")	       # -> "millenniums" or "millennia"
	       PL("ganglion")	       # -> "ganglions"	or "ganglia"
	       PL("octopus")	       # -> "octopuses"	or "octopodes"

       Lingua::EN::Inflect caters to such words	by providing an	"alternate
       state" of inflection known as "classical	mode".	By default, words are
       inflected using their contemporary English plurals, but if classical
       mode is invoked,	the more traditional plural forms are returned

       The exportable subroutine "classical()" controls	this feature.  If
       "classical()" is	called with no arguments, it unconditionally invokes
       classical mode. If it is	called with a single argument, it turns	all
       classical inflects on or	off (depending on whether the argument is true
       or false). If called with two or	more arguments,	those arguments
       specify which aspects of	classical behaviour are	to be used.


	       classical;		   # SWITCH ON CLASSICAL MODE
	       print PL("formula");	   # ->	"formulae"

	       classical 0;		   # SWITCH OFF	CLASSICAL MODE
	       print PL("formula");	   # ->	"formulas"

	       classical $cmode;	   # CLASSICAL MODE IFF	$cmode
	       print PL("formula");	   # ->	"formulae" (IF $cmode)
					   # ->	"formulas" (OTHERWISE)

	       classical herd=>1;	   # SWITCH ON CLASSICAL MODE FOR "HERD" NOUNS
	       print PL("wilderbeest");	   # ->	"wilderbeest"

	       classical names=>1;	   # SWITCH ON CLASSICAL MODE FOR NAMES
	       print PL("sally");	   # ->	"sallies"
	       print PL("Sally");	   # ->	"Sallys"

       Note however that "classical()" has no effect on	the inflection of
       words which are now fully assimilated. Hence:

	       PL("forum")	       # ALWAYS	-> "forums"
	       PL("criterion")	       # ALWAYS	-> "criteria"

       LEI assumes that	a capitalized word is a	person's name. So it forms the
       plural according	to the rules for names (which is that you don't
       inflect,	you just add -s	or -es). You can choose	to turn	that behaviour
       off (it's on by the default, even when the module isn't in classical
       mode) by	calling	"classical(names=>0)".

   Adding plurals at run-time
       Lingua::EN::Inflect provides five exportable subroutines	which allow
       the programmer to override the module's behaviour for specific cases:

	       The "def_noun" subroutine takes a pair of string	arguments: the
	       singular	and plural forms of the	noun being specified. The
	       singular	form specifies a pattern to be interpolated (as
	       "m/^(?:$first_arg)$/i").	 Any noun matching this	pattern	is
	       then replaced by	the string in the second argument. The second
	       argument	specifies a string which is interpolated after the
	       match succeeds, and is then used	as the plural form. For

		     def_noun  'cow'	    => 'kine';
		     def_noun  '(.+i)o'	    => '$1i';
		     def_noun  'spam(mer)?' => '\\$\\%\\@#\\$\\@#!!';

	       Note that both arguments	should usually be specified in single
	       quotes, so that they are	not interpolated when they are
	       specified, but later (when words	are compared to	them). As
	       indicated by the	last example, care also	needs to be taken with
	       certain characters in the second	argument, to ensure that they
	       are not unintentionally interpolated during comparison.

	       The second argument string may also specify a second variant of
	       the plural form,	to be used when	"classical" plurals have been
	       requested. The beginning	of the second variant is marked	by a
	       '|' character:

		     def_noun  'cow'	    => 'cows|kine';
		     def_noun  '(.+i)o'	    => '$1os|$1i';
		     def_noun  'spam(mer)?' => '\\$\\%\\@#\\$\\@#!!|varmints';

	       If no classical variant is given, the specified plural form is
	       used in both normal and "classical" modes.

	       If the second argument is "undef" instead of a string, then the
	       current user definition for the first argument is removed, and
	       the standard plural inflection(s) restored.

	       Note that in all	cases, later plural definitions	for a
	       particular singular form	replace	earlier	definitions of the
	       same form. For example:

		     def_noun  'aviatrix' => 'aviatrices';

		     def_noun  'aviatrix' => 'aviatrixes';

		     def_noun  'aviatrix' => undef;

	       Special care is also required when defining general patterns
	       and associated specific exceptions: put the more	specific cases
	       after the general pattern. For example:

		     def_noun  '(.+)us'	=> '$1i';      # EVERY "-us" TO	"-i"
		     def_noun  'bus'	=> 'buses';    # EXCEPT	FOR "bus"

	       This "try-most-recently-defined-first" approach to matching
	       user-defined words is also used by "def_verb", "def_a" and

	       The "def_verb" subroutine takes three pairs of string arguments
	       (that is, six arguments in total), specifying the singular and
	       plural forms of the three "persons" of verb. As with
	       "def_noun", the singular	forms are specifications of run-time-
	       interpolated patterns, whilst the plural	forms are
	       specifications of (up to	two) run-time-interpolated strings:

		      def_verb 'am'	  => 'are',
			       'are'	  => 'are|art',
			       'is'	  => 'are';

		      def_verb 'have'	  => 'have',
			       'have'	  => 'have',
			       'ha(s|th)' => 'have';

	       Note that as with "def_noun", modern/classical variants of
	       plurals may be separately specified, subsequent definitions
	       replace previous	ones, and "undef"'ed plural forms revert to
	       the standard behaviour.

	       The "def_adj" subroutine	takes a	pair of	string arguments,
	       which specify the singular and plural forms of the adjective
	       being defined.  As with "def_noun" and "def_adj", the singular
	       forms are specifications	of run-time-interpolated patterns,
	       whilst the plural forms are specifications of (up to two) run-
	       time-interpolated strings:

		      def_adj  'this'	  => 'these',
		      def_adj  'red'	  => 'red|gules',

	       As previously, modern/classical variants	of plurals may be
	       separately specified, subsequent	definitions replace previous
	       ones, and "undef"'ed plural forms revert	to the standard

       def_a($)	and def_an($)
	       The "def_a" and "def_an"	subroutines each take a	single
	       argument, which specifies a pattern. If a word passed to	"A()"
	       or "AN()" matches this pattern, it will be prefixed
	       (unconditionally) with the corresponding	indefinite article.
	       For example:

		     def_a  'error';
		     def_a  'in.+';

		     def_an 'mistake';
		     def_an 'error';

	       As with the other "def_..." subroutines,	such redefinitions are
	       sequential in effect so that, after the above example, "error"
	       will be inflected with "an".

   The $HOME/.inflectrc	file
       When it is imported, Lingua::EN::Inflect	executes (as Perl code)	the
       contents	of any file named .inflectrc which it finds in the in the
       directory where Lingua/EN/ is installed, or in	the current
       home directory ($ENV{HOME}), or in both.	 Note that the code is
       executed	within the Lingua::EN::Inflect namespace.

       Hence the user or the local Perl	guru can make appropriate calls	to
       "def_noun", "def_verb", etc. in one of these .inflectrc files, to
       permanently and universally modify the behaviour	of the module. For

	     > cat /usr/local/lib/perl5/Text/Inflect/.inflectrc

	     def_noun  "UNIX"  => "UN*X|UNICES";

	     def_verb  "teco"  => "teco",      # LITERALLY: "to	edit with TECO"
		       "teco"  => "teco",
		       "tecos" => "teco";

	     def_a     "Euler.*";	       # "Yewler" TURNS	IN HIS GRAVE

       Note that calls to the "def_..."	subroutines from within	a program will
       take precedence over the	contents of the	home directory .inflectrc
       file, which in turn takes precedence over the system-wide .inflectrc

       On loading, if the Perl code in a .inflectrc file is invalid
       (syntactically or otherwise), an	appropriate fatal error	is issued.  A
       common problem is not ending the	file with something that evaluates to
       true (as	the five "def_..." subroutines do).

       Using the five "def_..."	subroutines directly in	a program may also
       result in fatal diagnostics, if a (singular) pattern or an interpolated
       (plural)	string is somehow invalid.

       Specific	diagnostics related to user-defined inflections	are:

       "Bad user-defined singular pattern:\n\t %s"
	       The singular form of a user-defined noun	or verb	(as defined by
	       a call to "def_noun", "def_verb", "def_adj", "def_a" or
	       "def_an") is not	a valid	Perl regular expression. The actual
	       Perl error message is also given.

       "Bad user-defined plural	string:	'%s'"
	       The plural form(s) of a user-defined noun or verb (as defined
	       by a call to "def_noun",	"def_verb" or "def_adj") is not	a
	       valid Perl interpolated string (usually because it interpolates
	       some undefined variable).

       "Bad .inflectrc file (%s):\n %s"
	       Some other problem occurred in loading the named	local or
	       global .inflectrc file. The Perl	error message (including the
	       line number) is also given.

       There are no diagnosable	run-time error conditions for the actual
       inflection subroutines, except "NUMWORDS" and hence no run-time
       diagnostics. If the inflection subroutines are unable to	form a plural
       via a user-definition or	an inbuilt rule, they just "guess" the
       commonest English inflection: adding "-s" for nouns, removing "-s" for
       verbs, and no inflection	for adjectives.

       "Lingua::EN::Inflect::NUMWORDS()" can "die" with	the following

       "Bad grouping option: %s"
	       The optional argument to	"NUMWORDS()" wasn't 1, 2 or 3.

       "Number out of range"
	       "NUMWORDS()" was	passed a number	larger than the	number
	       represented by 3006 consecutive nines. The words	representing
	       that number are 63,681 characters long, including commas	and
	       spaces. If you're interested in the actual value, see

	       The reference for the names is

	       There are no names for any higher numbers.

   2nd Person precedence
       If a verb has identical 1st and 2nd person singular forms, but
       different 1st and 2nd person plural forms, then when its	plural is
       constructed, the	2nd person plural form is always preferred.

       The author is not currently aware of any	such verbs in English, but is
       not quite arrogant enough to assume ipso	facto that none	exist.

   Nominative precedence
       The singular pronoun "it" presents a special problem because its	plural
       form can	vary, depending	on its "case". For example:

	       It ate my homework	->  They ate my	homework
	       It ate it		->  They ate them
	       I fed my	homework to it	->  I fed my homework to them

       As a consequence	of this	ambiguity, "PL()" or "PL_N" have been
       implemented so that they	always return the nominative plural (that is,

       However,	when asked for the plural of an	unambiguously accusative "it"
       (namely,	"PL("to	it")", "PL_N("from it")", "PL("with it")", etc.), both
       subroutines will	correctly return the accusative	plural ("to them",
       "from them", "with them", etc.)

   The plurality of zero
       The rules governing the choice between:

	     There were	no errors.


	     There was no error.

       are complex and often depend more on intent rather than content.	 Hence
       it is infeasible	to specify such	rules algorithmically.

       Therefore, Lingua::EN::Text contents itself with	the following
       compromise: If the governing number is zero, inflections	always return
       the plural form unless the appropriate "classical" inflection is	in
       effect, in which	case the singular form is always returned.

       Thus, the sequence:

	     print inflect "There PL(was) NO(choice)";

       produces	"There were no choices", whereas:

	     classical 'zero';	   # or: classical(zero=>1);
	     print inflect "There PL(was) NO(choice)";

       it will print "There was	no choice".

   Homographs with heterogeneous plurals
       Another context in which	intent (and not	content) sometimes determines
       plurality is where two distinct meanings	of a word require different
       plurals.	For example:

	     Three basses were stolen from the band's equipment	trailer.
	     Three bass	were stolen from the band's aquarium.

	     I put the mice next to the	cheese.
	     I put the mouses next to the computers.

	     Several thoughts about leaving crossed my mind.
	     Several thought about leaving across my lawn.

       Lingua::EN::Inflect handles such	words in two ways:

       o       If both meanings	of the word are	the same part of speech	(for
	       example,	"bass" is a noun in both sentences above), then	one
	       meaning is chosen as the	"usual"	meaning, and only that
	       meaning's plural	is ever	returned by any	of the inflection

       o       If each meaning of the word is a	different part of speech (for
	       example,	"thought" is both a noun and a verb), then the noun's
	       plural is returned by "PL()" and	"PL_N()" and the verb's	plural
	       is returned only	by "PL_V()".

       Such contexts are, fortunately, uncommon	(particularly "same-part-of-
       speech" examples). An informal study of nearly 600 "difficult plurals"
       indicates that "PL()" can be relied upon	to "get	it right" about	98% of
       the time	(although, of course, ichthyophilic guitarists or cyber-
       behaviouralists may experience higher rates of confusion).

       If the choice of	a particular "usual inflection"	is considered
       inappropriate, it can always be reversed	with a preliminary call	to the
       corresponding "def_..." subroutine.

       I'm not taking any further correspondence on:

	   Despite the populist	pandering of certain New World dictionaries,
	   the plural is "octopuses" or	(for the pedantic classicist)
	   "octopodes".	The suffix "-pus" is Greek, not	Latin, so the plural
	   is "-podes",	not "pi".

	   Had no plural in Latin (possibly because it was a mass noun).  The
	   only	plural is the Anglicized "viruses".

       Damian Conway (

       The endless inconsistencies of English.

       (Please report words for	which the correct plural or indefinite article
       is not formed, so that the reliability of Lingua::EN::Inflect can be

	Copyright (c) 1997-2009, Damian	Conway.	All Rights Reserved.
	This module is free software. It may be	used, redistributed
	    and/or modified under the same terms as Perl itself.

perl v5.32.1			  2020-12-08		Lingua::EN::Inflect(3)


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