1. MUST & MUSTN’T

2. We use must not to say that something is not permitted or allowed, for example: Passengers must not talk to the driver. Mustn't I mustn't eat so much sugar. You mustn't watch so much television. Students must not leave bicycles here. Policemen must not drink on duty. The prohibition can be (the speaker's opinion) or (a real law or rule). Look at these examples:

3. What do these signs mean? Write what you must or mustn’t do? HARD HAT AREA KEEP OFF GRASS PASSPORT CONTROL Remember! You …………………… eat or drink in the museum, and you …………………… take any photos! And you …………………… touch the paintings or statues. Be good! Please! You …………………… speak English. You ……………… raise your hand to ask a question. You …………………… bring your book in class but you …………………… use it in an exam.