You're right; the clause subject 'the use' is a singular noun so the agreement between the subject and the verb in the clause make you use 'is'.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.
Anonymousis this a correct sentence/grammar? "What we are testing here are your lungs?" What "verb to be" are we going to use for the word LUNGS?You have presented yourself with an unnecessary conundrum. The wise writer recasts: