have to and don't have to — obligation and no obligationSaying what is necessary and what is not necessary.Related learning areasEnglish GrammarRelated conceptsas … as for saying things are the sameAuxiliary verbs in short answersbe going to — plans and intentionsbe going to — predictions from present evidenceChoosing between present, past, and future verb formsComparative adjectivesLeads tomust and mustn't — rules and prohibitionQuestionsAll questions in this subjectStart learningStart free practice