5. Read the Look out! box. Then, using the words in brackets, rewrite the sentences so that they have the same meaning.
LOOK OUT!
a. must and have to are very similar. However, must often expresses the feelings of the speaker. (must và have to rất giống nhau. Tuy nhiên, must thường thể hiện cảm xúc của người nói.)
You must do more exercise. (That's my strong opinion.) (Bạn phải làm nhiều bài tập hơn nữa.) (Đó là một quan điểm rất mạnh.)
have to often expresses an external obligation. (have to thường chỉ sự bắt buộc từ bên ngoài.)
You have to wear a helmet. (It's the law.) (Bạn phải đội mũ bảo hiểm.) (Đây là luật.)
b. mustn't and don't have to do NOT have the same meaning. don't have to = needn't, but mustn't means 'it is prohibited’. (mustn’t và don’t have to không cùng nghĩa. don’t have to = needn’t, nhưng mustn’t nghĩa là “nó bị cấm”.)
1 It isn't necessary for you to help me. (needn't)
2 It's compulsory for us to wear school uniform. (have to)
3 You aren't allowed to talk in the exam. (mustn't)
4. It's important that you listen to me. (must)
5. You needn't write the answer. (have to)