`1`. If you have a headache, you should have an aspirin.

`-` Câu điều kiện loại `1`: If + S + V(-s/es), S + will/modal verbs + V-inf

`2`. You shouldn't play music loud after midnight.

`-` S + shouldn't + V-inf: không nên làm gì

`3`. You should knock the door before you enter the room.

`-` S + should + V-inf: nên làm gì

`-` S + V + before + S + V: ... trước khi ...

`-` HTĐ: S + V(-s/es)

`4`. You shouldn't break things at Tet.

`-` at + ngày lễ đặc biệt

`-` break things (v): làm hỏng/vỡ đồ

`5`. You should say the New Years greetings before you get lucky money.

`-` get lucky money (v): nhận tiền lì xì

`1.` If you have a headache, you should take an aspirin

`-` S + has/have  +  a  disease: ai đó bị gì

`-` take an aspirin: uống một viên aspirin

`2.` You shouldn't play music loud after midnight

`3.` You should knock the door before you enter the room

`-` before+V-ing/a clause: trước khi .... 

`4.` You should break things at Tet

`5.` You should say the New Year's greetings before you get lucky money

`______________________`

`***` S  +  should  +  V-inf  +.... : ai đó nên làm gì