Usage and Grammar

Q. Hello, arbiters of messy prose. In a scholarly work on global labor conditions, plural-singular nonagreement involving the word “ability” occurs about fifty times, as in “Rules regarding paid leave affected families’ ability to earn a living.” My instinct is to change “ability” to “abilities” in this and similar cases, but is it really necessary? Thanks!

A. In your sentence, the singular seems right, but sometimes the plural can work if the noun is less abstract and more countable than “abilities”: Rules regarding paid leave affected families’ savings accounts. The plural would also work if “abilities” were used in a slightly more countable, and thus more properly plural, way: Special education can improve students’ abilities in several areas. The singular works best with abstractions that the possessors share in the singular: The new cafeteria menu affected the students’ morale.