Plural Formation

The abstract of a paper at http://www.csse.monash.edu.au/~damian/papers/HTML/Plurals.html says:

This paper discusses some of the issues involved in designing robust and comprehensive algorithms which convert singular English nouns, verbs and adjectives to their appropriate plural forms. Four such algorithms are given: one for each part of speech which inflects in the plural, and a unified algorithm for all such parts of speech. A word comparison algorithm which can identify words which differ only in their grammatical number is also given. Finally, an overview is given of a full implementation of the various algorithms in the Perl [1] programming language.

Plural categories are presented in tabular form in an Appendix at http://www.csse.monash.edu.au/~damian/papers/HTML/Plurals_AppendixA.html.

Despite the fact that the paper addresses pluralization as a computer-algorithm problem, it should also be interesting to English students as a review and summary of the ways plurals are formed.