"I barraged him with an interview."
The above sentence sounds wrong to me.
I feel like you should barrage someone with either a plural (such as "I barraged him with questions.") or one of those terms that is technically singular but actually represents a multiple things, for example "I barraged him with a bunch of questions".
But given that "a bunch" is technically singular, doesn't that mean my original sentence "I barraged him with an interview," is technically grammatically correct?
Dictionary.com defines barrage (noun) as
an overwhelming quantity or explosion, as of words, blows, or criticisms
and defines barrage (verb) as
to subject to a barrage
To barrage someone with an interview is probably grammatically correct in the sense given above, but idiomatically it's pretty clunky.
I'd suggest I subjected him to a barrage of questions during the interview which would convey all the ideas you're trying to get across.
In your example, "a bunch of" is a determiner for "questions." You're not asking "a bunch," you're asking questions, of which there are a bunch.
You are correct that you should barrage with a plural.
