These are both correct: What will I do when he interrogates me? What will I do if he interrogates me?
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.
RayHThese are both correct:
What will I do when he interrogates me?
What will I do if he interrogates me?
In addition, I would (personal preference) use 'while' instead of 'when'.
Debpriya De Is it right that we cannot use will twice in such sentences which involve future tense ?Generally speaking, yes. Don't use will after adverbial conjunctions of time or after if. (There are exceptions, but this is the general rule.)