Lesson 26 mustn’t / don’t have to
Choose the correct answers:
- People under twenty-one years old __________ (mustn’t, don’t have to, didn’t have to) drink alcohol, but they can drink juice
- People at and over twenty-one years old __________ (mustn’t, don’t have to, didn’t have to) drink alcohol. They can choose juice.
- At twenty-one, I am allowed to drink alcohol, but I __________ (mustn’t, don’t have to, didn’t have to) drink too much because I will need to drive afterwards.
Explain:
Even though “must” and “have/has to” have similar meanings in the positive forms, they are very different in negative sentences.
mustn’t: not allowed. It shows clear prohibition, no choice.
don’t/doesn’t/didn’t have to: no need, not necessary. It implies a choice.
- In Sentence #1 and #3, there is no choice because of the law.
- In Sentence #2, people can choose to drink alcohol or not to drink it. It is not necessary to drink alcohol if they do not want to.
Review:
- An elementary school pupil __________ (mustn’t, doesn’t have to, didn’t have to) stay home alone on a school holiday.
- A high school student __________ (mustn’t, doesn’t have to, didn’t have to) stay home alone on a school holiday. He or she may choose to relax at home or visit friends.
- As a college student, my schedule is flexible. For example, I__________ (mustn’t, don’t have to, didn’t have to) get up early last Monday because my classes are on Tuesdays and Thursdays.
Answers:
mustn’t; don’t have to; mustn’t
mustn’t; doesn’t have to; didn’t have to
