Mike ( had broken | broke ) his mother's vase last night but he has not told her yet.
Question: Some argue it must use "broke" instead of "had broken" because "last night" could not be used with past perfect tense. I notice some teachers preach a grammar rule: Adverb like "last night, last year, a few days ago" should not be used with past perfect tense; It should use past tense. But I never find any formal grammar books make that statement. Instead, I think it is quite a "weak grammar rule" which is often "violated" in some writings. I have quite often seen sentences like "He had taken the test last year." and similar ones in popular novels, news papers and magazines.
I think "had broken" is a better answer here as it make the sentence more cohesive in meaning and logic, even though "broke" is ok too, at least grammatically.
Maybe only in cases for a specific time point like "at 8 o'clock", we might have to use past tense. e.g, He broke the vase at 8 pm last night.
Please enlighten me on this if my understanding is not right or there is some grammar rules prevailing here which I am not aware of.
Your advise are appreciated very much!