That + when, where

Why do you think the “when and where” have anything to do with your question?.

The main verbs are the clue.

I was indecisive because as I know it is normal to say: "I know where you were," or "I can told you when she will come," i.e. we say it without "that." Of course, just like after "who," "what," etc. I think that "that" is omitted because we stress "when," "where," etc. But above my sentences are of another type, and I don't know if I understand well that therefore you too suggest using "that" in these sentences.