At work, the client requested, if existing search engine could accept singular and plural forms equally, e. g. “partner” and “partners” would lead to the same result. The first option – stemming. In that case, search engine would use root of a word, e. g. “partn”. However, stemming has many weaknesses: two different words might have same root, a

Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).