I found this sentence in a book written for English learners:
He does nothing but chase girls all day.
But I feel that ‘chase’ should have been ‘chases’ (so to agree with the sentence subject ‘he’). I think the sentence above is a short form for:
He does nothing but he chases girls all day.
Am I right? Thanks.
Following “does,” verbs are in the bare infinitive. See these sentences:
He didn’t always love her.
He usually doesn’t return calls.
She doesn’t ask before taking her lunch break.
Also, the “s” on the end of “chase” doesn’t make it plural, it in fact marks it as conjugated for the third person singular.