Must and need are modal auxiliary verbs. Must expresses ideas as such as strong obligation, compulsion etc. Need expresses ideas such as necessity. Must not shows prohibition. Need not shows lack of obligation or necessity.
Fill in the blanks with must not or need not.
1You ............... invite Sabu. I don't want him to come.
Wrong!
Use "must not" because the speaker is forbidding the invitation.
2You ............... invite her. She won't come.
Wrong!
Use "need not" because the invitation is unnecessary.
3You ............... tell anybody about my decision. It is a secret.
Wrong!
Use "must not" because telling anyone is forbidden.
4You ............... make a noise. The baby is sleeping.
Wrong!
Use "must not" because making noise is forbidden.
5You ............... reserve a table. It is not very busy in the morning.
Wrong!
Use "need not" because reserving a table is unnecessary.
6You ............... quit this job before you find another one.
Wrong!
Use "must not" because quitting before finding another job is a strong warning.
7You ............... waste your time on idle pursuits.
Wrong!
Use "must not" because wasting time is being strongly prohibited or advised against.
8Those who have already registered ............... register again.
Wrong!
Use "need not" because registering again is unnecessary.
9You ............... rush. You can take your time.
Wrong!
Use "need not" because rushing is unnecessary.
10You ............... told her. She already knew about it.
Wrong!
Use "need not have" because telling her was unnecessary in the past.
11You ............... waste food.
Wrong!
Use "must not" because wasting food is being strongly prohibited or advised against.
12You ............... cooked so much food. Nobody was hungry.
Wrong!
Use "need not have" because cooking so much was unnecessary in the past.
Done.
Score: 0/12
Answers
- You must not invite Sabu. I don’t want him to come.
- You need not invite her. She won’t come.
- You must not tell anybody about my decision. It is a secret.
- You must not make a noise. The baby is sleeping.
- You need not reserve a table. It is not very busy in the morning.
- You must not quit this job before you find another one.
- You must not waste your time on idle pursuits.
- Those who have already registered need not register again.
- You need not rush. You can take your time.
- You need not have told her. She already knew about it.
- You must not waste food.
- You need not have cooked so much food. Nobody was hungry.
