I would like to know what the correct way to indicate a singular/plural pair is when the singular ends in -y and the plural in -ies.
With book you can use book(s) to indicate in writing how to form the plural from the singular, but with party, would you use party(ies) or party(s) or something else?
Is there a reference where rules are provided for this?
This question deals with this ‘optional (s)’, but does not mention how to add the (s) if a change in the base word also has to occur.
