Matching Pairs Must have toOnline version The correct use of must , have to and their negative form by Sabs Negrete 1 Forbidden or not allowed to do 2 Not necessary and you can choose 3 A personal very important, necessary thing to do 4 Formal or written obligations 5 It isn't necessary, just and advice 6 You have no choice. 7 It is an obligation from the situation. SHOULD & SHOULDN'T MUST HAVE TO MUST HAVE TO MUST NOT DON'T HAVE TO