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