`1.` He was too small to see over the wall.

`2.` He wasn't big enough to see over the wall.

`3.` He was so small that he couldn't see over the wall.

`4.` He was such a small boy that he couldn't see over the wall.

`@` Kiến thức :

`-` S + Be/V + too + adj/adv + (for someone) + to do something: Quá....để cho ai làm gì...

`-` S + Be/V + adj/ adv + enough + (for someone) + to do something : Đủ... cho ai đó làm gì...

`-` S + Be/V + so + adj/ adv + that + S + V+O: Quá... đến nỗi mà... 

`-` It + Be/V + such + (a/an) + (adj) + N(s) + that + S + V +O: Quá... đến nỗi mà...

*Answer : He was too small to see over the wall

-> He wasn't big enough to see over the wall

-> He was so short that he couldn't see over the wall

-> He was such a short boy that he couldn't see over the wall

*Giải thích:

- S + be/V + too + adj/adv + (for sb) + to V

- S + be/V + adj/adv + enough + (for sb) + to V

- S + be + so + adj + that + clause

- S + be + such + (a/an) + adj + N + that

*Chú ý : 

- S + be + too + adj+ (for sb) + to V

-> S + be + not + too + tính từ trái nghĩa + (for sb) + to V