1. I'm not allowed to watch tv before going to bed( must) -> I...... 2. It is neccesary for you to help us( need) -> You.... 3. It's important to study hard this year( must) -> You...... 4. It's not compulsory to take part in the school competion ( have to) -> We..... 5. It is neccesary to go to bed early on weekdays ( have to) -> We..... Giúp m với ạ

`1`.I mustn't watch TV before going to bed

`->` S + must / mustn't + V-inf ( `1 , 3` )

`=>` Phải / Không được phép làm gì

`2`.You need to help us

`->` need + to do sth

`=>` Cần phải làm gì

`3`.You must study hard this year

`4`.We don't have to take part in the school competition

`->` S + don't / doesn't / ... + have + to do sth

`=>` Không cần phải làm gì

`5`.We have to go to bed early on weekdays

`->` S + have / has / ... + to do sth

`=>` Bắt buộc phải làm gì

`\text{# TF}`

`1` I musnt not watch TV before going to bed 

`-` be not allowed to do sth 

`=` mustn't do sth: không được làm gì

`2` You need to help us 

`-` It is necessary for + O + to do sth 

`=` S + need + to do sth: cần làm gì 

`3` You must study hard this year

`-` It is important for + O + to do sth : quan trọng để làm gì 

`=` S + must+ do sth: phải làm gì 

`4` We don't have to take part in the school competion

`-` It is not compulsory for + O + to do sth : ko bắt buộ

`=` S + don't/ doesn't have to/need to +  do sth:không cần làm gì 

`5` We have to go to bed early on weekends

`-` It is necessary for + O + to do sth 

`=` S + have to/need to + do sth: cần làm gì