The Lingua::EN::Inflect::Number module extends the functionality of
 Lingua::EN::Inflect (the liblingua-en-inflect-perl package) with three new
 functions.
 .
 number() takes a word, and determines its number. It returns whether
 the word is singular, plural, or ambiguous for words that can be
 either singular or plural.
 .
 Based on the number() function there are to_S() and to_PL() which
 take a word and convert it forcefully either to singular or to
 plural. In Lingua::EN::Inflect funny things happen if you try to
 pluralise an already-plural word, but this module does the right
 thing.