Q. When you use parentheses to indicate that a noun might be plural, is it necessary to use them to indicate that the verb might be plural as well? For example, The participant(s) was (were) informed of the procedure in writing. Is there a rule about this, or is it a stylistic choice? Am I justified in adding the second verb to an author’s manuscript?
A. I don’t know about a rule, but the construction is clumsy, and it’s better to avoid it. Just write “Participants were informed of the procedure in writing,” which doesn’t rule out the possibility of there being only one participant.