No, not at all. You can use any verb form with this phrase. Past perfect, present perfect, conditional, future, etc. It does not make any difference. It just depends on what you want to communicate. Examples: 1. If you would wash the dishes more often, then I would be grateful. 2. If she had been smiling, (then) I would have spoken to her. 3. If they will just be quiet, then you can read your book. "If (condition), then (result)" is how the phrase should be used. The verb tense does not necessarily matter.

Very depends on the condition.

Hi! Also see this site: http://en.wikipedia.org/wiki/Conditional_sentence