`26.` I haven’t seen Bob since I was in Ho Chi Minh City.

`-` S + last + Ved/ V2 `->` S + haven't/ hasn't + V(pp)

`-` when + QKĐ `->` since + QKĐ

`-` see - saw - seen: nhìn

`-` Thì hiện tại hoàn thành: S + have/ has + not + V(pp)

`27.` If Chris had to work hard, he would pass his exams.

`-` Nếu 1 trong 2 vế chia ở thì hiện tại, vế còn lại chia ở thì hiện tại hoặc tương lai `->` Câu điều kiện loại `2`

`-` Công thức: If + S + Ved/ V2, S + would/ could/ might/... + Vinf

`28.` Although he had a good salary, he was unhappy in his job.

`-` Despite + N/ N phrase/ V-ing `=` Although + clause: Mặc dù

`29.` She is not old enough to see that movie.

`-` Cấu trúc: S + to be + (not) + adj + enough + to V

`30.` Nobody in my class is taller than Jane.

`-` So sánh hơn với tính từ ngắn: 

S1 + to be + (not) + short adj-er + than + S2.

`26`.I haven't seen Bob since I was in Ho Chi Minh City

`\rightarrow` Thì HTHT : S + have / has + V3 / PII

`\rightarrow` Đặc điểm nhận dạng : since

`27`.If Chris he has to work hard , he will pass his exams

`\rightarrow` CĐK loại 1 :

`-` If - clause : Thì HTĐ : S + V s / es / không s , es

`-` Main - clause : Thì TLĐ : S + will + V

`28`.Although he had a good salary , he was unhappy in his job

`\rightarrow` Although + C1 + C2 : Mặc dù

`29`.She is not old enough to see that movie

`\rightarrow` Enough : S + be / be not + adj + enough ( for O ) + to do sth

`30`.Nobody in my class is taller than Jane

`\rightarrow` So sánh hơn : S1 + be + adj-er / more adj + than + S2

`\text{@ TheFox}`