I know how to pluralize a name under normal circumstances.

Name pear%s%

But I have an item where the end of the word changes depending on whether it is singular or plural.
For example, the word leaf (singular) and leaves (plural). Does POL have a way to handle words such as that?

Of course
It's eg
start%plural/singular%rest
So in your example it should be
lea%ves/f

Btw try:
uotool formatdesc lea%ves/f

Thank you Turley.