Recently I came upon these sentences in one of my exercises, and I was wondering whether time "continuity" or chronology was disrupted here.
Task: "There are mistakes in eight of these sentences. Correct the sentences where necessary. Write 'Ok' if the sentences is already correct".
We can't remember where did we leave our car.
My version: We can't remember where we have left our car.
Author's version: We can't remember where we left our car.
Now I know why didn't you tell me what you were buying!
My version: Now I know why you haven't told me what you were buying!
Author's version: Now I know why you didn't tell me what you were buying!
Imprimis, I am not a native speaker, however, I have been told that you can't mix up certain tenses, for instance, Present Simple + Past Simple etc.