Isn't there a module that does this already? Something using Lingua::EN::Inflect? There's a key difference though between something that is singular and plurar - you expect to be able to pass more than one to a plural function. This might mean a different calling convetion like func( $elt )/func( \ @elts )/func( $elt1, $elt2, ... ) and it isn't obvious which one would be used since there's no convention for that kind of thing.