Quote Originally Posted by Lampada View Post

Будет ли у тебя свободное время завтра? = Будешь ли ты иметь свободное время завтра?
Dale, you should pay special attention to this example by Lampada. Both sentences mean the same thing -- Will you have free time tomorrow? -- but in the first one, время is the subject and takes the 3rd-person singular будет, while in the second, ты is the subject and takes the 2nd-sing. будешь. (And the first sentence sounds much more natural, while the second one "isn't wrong, but sounds weird".)

Also, by the way, Время будет у нас means "We we will have time", but Павел будет у нас does not mean "We will have Pavel"! Instead, it means "Pavel will be at our place."

But suppose you want to say "We will be at our place". In that case, you don't say Мы будем у нас -- but it's possible to say Мы будем у себя (дома), using the reflexive pronoun себя ("oneself") instead of the 1st-person plural нас ("us"). Or you can just say Мы будем дома ("We will be at home"). Either way, I think Боб Уайтман is correct that "будем у нас" is never used.