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What is the correct possessive for nouns ending in s?
"Please submit your and your parent(s)' federal tax returns." Is the possessive of "parent(s)'" correctly formatted in that sentence? I know the apostrophe comes before the "s" for just parent singular, and it would come after the "s" for parents plural, but what if I don't know if it is one or two parents, and therefore want to use the (s)?