Use 'have to' in the past, present, and future to express responsibility or necessity. English; Learner’s Dictionary; Essential British English; Essential American English; Translations. The verbs need, have to, and must are all synonyms of one another and are used to mean that something is necessary or required. Definitions. Need, when followed by to and a verb, is the narrowest of the three verbs. You don't need to go shopping as I've already gone. But they each have slightly different connotations and uses. Clear explanations of natural written and spoken English . Listed below are explanations, examples, and uses of must / have to / need to / and mustn't / not have to / don't need to. Have to Do—Responsibilities. Need - English Grammar Today - a reference to written and spoken English grammar and usage - Cambridge Dictionary . Cambridge Dictionary +Plus; My profile +Plus help; Log out; Dictionary .