When Can I use (to, that) and when can not Hello, I am confused about the usage of "to" or "that" in the following sentences. 1) I am going to sleep to the bedroom (Is it Ok?) 2)I think that we must arrive early / I think we must arrive early (which one is ok or is more common and natural) 3)I want to go to the restaurant (Is it Ok?) 4) I need to see to my parents / I need to see my parents (which one is ok or is more common and natural) 5) I don´t know what to say / I don´t know what saying (which one is ok or is more common and natural)