Are "It is important for you to exercise." and "It is important to you to exercise." both grammatically right?

They are both correct, but the meanings are slightly different. 'It is important to you to exercise,' is saying the person to whom you are speaking considers exercise to be important. 'It is important for you to exercise,' is saying that you believe it is important for the person to whom you are speaking to exercise.

There are subtle nuances between the two; therefore, both are correct in different circumstances.

I important for you personally to exercise because you have a weight problem. Here the stress is on the personal exercise.

It important to you to exercise because you actually believe it is essential for your well being' Here, 'exercise' is a personal value to the person, who may, or, may not be,overweight. He just values all exercise intellectually.

In any case, the difference is so slight that n ative speakers would have no problem knowing what is meant from the context of the conversation.

The first one is grammatically correct, but I'm unsure that the second one is. I guess, in a way, it makes sense, but people tend to use the first option more often.

happy birthday to you - real fact

important for you to - not necessary fact