1. MODAL VERBS Must Must not (Mustn’t)

2. Modal Verbs We use must when the speaker personally feels that something is important. Examples: You really must stop working so hard and try to relax. You must be here by 8 a.m., or the bus will leave without you. English

3. Modal Verbs In the negative form, mustn't describes an action that is prohibited/forbidden. Examples: You mustn’t cross the road when the red light is showing. You mustn’t smoke here. English

4. Modal Verbs We use Have to describe an obligation that should be fulfilled in order to respect the law or an agreement. Examples: You have to be here by 8 a.m., or the bus will leave without you. I have to go to the dentist, I have an appointment at 3 p.m. English

5. Modal Verbs Don't have to describes an action that is not necessary – you have a choice. Example: You don’t have to turn on the central heating. It’s automatic. English