Don't ask it when you will die.

I doubt many people want to know that answer anyways.

*realises that it was in the original post.*

I read it as "what should I NOT ask my pendulum"...oopse

Whats another one, lets see.....

Asking about births and genders of babies seems to me to be a bit of a hard one.

Asking about whether someone loves you before you know enough about them to know them properly yourself would also give some contradictory answers.

Hmm...asking about past lives can get tricky too. My friend asked "have I had more than *insert number* of lives" and kept getting confusing answers.

I think maybe pendulums hone in on what your subconscious already knows and reacts to that..so that could be why some things are best left unquestioned....but that's just a little theory of mine.