This document provides instructions and examples for using must and mustn't to express obligations and prohibitions in English. It contains 4 parts: 1) Examples of must and have to and the source of the obligations. 2) Completing sentences with mustn't. 3) Completing sentences about daily routines and obligations using must and mustn't. 4) More examples of completing sentences with must and mustn't about obligations and prohibitions. The document aims to teach English learners how to properly use and distinguish must and mustn't.

1. Practice File_Expressing Obligation: Must /mustn’t
Part I. Watch the video and write the rules for the examples below:
• I must go to school. I must have a hair cut. (obligation comes from ................................)
• I have to go to school. I have to have a hair cut. (obligation comes from .............................)
Part II. Watch the video and complete the sentences
1. You __________smoke here. = you ________smoke here. It is prohibited.
2. You ___________ smoke here. = you ________ smoke here if you want, but it is not necessary.
3. We ___________work tomorrow. It’s a holiday.
4. You __________ take the bus to school. It’s too far to walk.
5. It’s late. I ___________go now.
6. You __________step on the grass. It is prohibited.
Part III. Watch the video and complete the sentences:
Situation_1
You _________ feed the dog everyday.
You _________lock the door and close all the windows before you sleep.
Situation_2
You _________brush your teeth 3 times a day.
You ________ wash your face when you wake up.
Situation_3
You_________eat in a library.
You________smoke in a library.
You_______return the books to their places.
Part IV. Watch the video and complete the sentences:
1. You ________ finish your homework
2. You ________ be quiet. The baby is sleeping.
3. You ________ drive here. It is a bicycle lane.
4. You ________ look for another parking spot. You can park here.
5. You ________ fasten your seatbelt.
6. Every man ________ do their millitary service in my country. It is obligatory.
7. Policemen ________ wear a uniform.
8. Teachers ________ wear a uniform.