Is the sentence correct?

I would restate it this way for clarity:

I don't remember when the last time was when I went to the cinema.

Or: "I don't remember when I last went to the cinema."

Re: Is the sentence correct?


It isn't a question of "correct", Tanguatlay. When we don;t have a question, we normally don't used question forms, ie. 'subject-verb' inversion.

Your example, above, is certainly a possibility and they are quite common in language.