`1`.He has a toothache

`\rightarrow` Thì HTĐ : S + Vs / es ( `1 , 3` )

`\rightarrow` a pain in his tooth `=` toothache : đau răng

`2`.What's the matter with your mother ?

`\rightarrow` Hỏi bệnh nền :

`=>` What + is / was / ... + the matter + with sb ?

`3`.My brother often walks to school

`\rightarrow` `DHNB` : often

`\rightarrow` goes on foot `=` walks : đi bộ

`4`.They went to the city centre by bus

`\rightarrow` Thì QKĐ : S + Ved / V2

`\rightarrow` By + Phương tiện di chuyển

`5`.He shouldn't ride his bike too fast

`\rightarrow` S + should / shouldn't + V-inf : Nên / Không nên làm gì

`\rightarrow` had better ( not ) `=` should ( not ) : ( Không ) nên

`\text{# Eternal}`