Past tense and prepositions

Question

I thought you have never responded to my last email. It turned out it was overlooked.

Are (the) prepositions and past tenses used in the above 2 sentences correct?

Answer 1

You should not use a present perfect in either sentence, since the events in the head clauses—the clauses which name your thought and the discovery of the true state of affairs—are in both cases situated in the past:

I thought ...
It turned out ...

Those two past tenses establish a past Reference Time (RT), and the other clauses must be ‘referred’ (related) to that.

In both cases, the subordinate clauses—those which describe the failure to respond and the oversight—involve actions prior to the thought and the discovery, and both name states which obtained at those two times.

• In the first sentence that state is the state of ‘non-response’ you believed to be true (it is not relevant that you were still expecting a response, because your expectation is outside the sentence); that state is what gave rise to your thought.

• In the second state, that state is the state of ‘overlooked-ness’; that is the state which was discovered to be true.

A current state which a prior event gives rise to is precisely what a perfect construction describes. Since your RT is past, what is called for in each case is a past perfect. Consequently, what you must write is:

I thought you had never responded to my last email. It turned out it had been overlooked.

If this explanation is too brief, you may find a great deal more about the meaning and use of perfect constructions at What is the perfect, and how should I use it?, especially §3.1 Grammatical meaning and §3.2 Pragmatic meaning; §4 When and how should I use the perfect? may also be of interest to you.