The verb following DO is not in present form but in the infinitive form. (To be sure, this is a rather artificial distinction, since in most cases the two forms are identical; but they are different for one very common verb, BE.)
Accordingly, there's no present form here to confuse you. Forgot is the form you want.
However, in this context forget takes a bare infinitive rather than a gerund, so the expressions you're looking for are:
Did you forget to switch it off?
You forgot to switch it off, didn't you.
Forgot to switch it off, did you?
No comments:
Post a Comment