I rarely have time for much because I'm studying very hard, and I don't speak English well, so can't you get often because I might not understand what you say.
I do not have much time to you because I am studying very hard and I could not speak English very well, so you have to call them because I could not understand what you are saying.
I don"t have time for you? Because I"m studying hard, and I can"t speak English very well, so could you call frequently because I could not understand what you are saying.