English — Expressing Obligation and Prohibition: Must, Mustn’\”t, Have to, Don’\”t Have to — 3rd Year Middle School — Algerian Curriculum

Expressing Obligation and Prohibition: Must, Mustn’t, Have to, Don’t Have to

Expressing rules and obligations. Must (strong obligation from speaker): You must wear a uniform. Mustn’t (prohibition): You mustn’t run in the corridor. Have to (external obligation): I have to wear a uniform at school. Don’t/doesn’t have to (no obligation): You don’t have to come if you don’t want to. Should (advice): You should study more. Shouldn’t (advice against): You shouldn’t eat too much sugar. Need to (necessity): I need to finish this work. Questions: Do I have to? Must I? Comparing: must is stronger than should; have to is external, must is internal.