Make some questions and answers as to the traffic light(s) наприклад:-Can i cross the road when the light is red? -No,you mustn*t .You should cross it when the light is green. Must we...? May she...? Could you...?
- Must we clean our room every day? - No we mustn't. We must clean our room once a week. - Could you help me? - No you couldn't help her. You should turn to someone else.