1) goes→ go

( vì S+don't+$V^{0}$ + O)

2) oldest→ older

có than ,so sánh hơn, 

S1+be+adj+than+S2

3) don't→ doesn't

vì he +doesn't

They don't goes to bed at 9 o'clock

HTĐ : ( - ) S + do / does + not + V + O

`V` ở đây phải là `V_base` vì phủ định

She is oldest than her sister

SSH ( tính từ ngắn ) : S + be + Adj- er + than + O

He don't like fish

HTĐ : ( - ) S + do / does + not + V + O

`S` ở đây là He `=>` doesn't

`tuan`