He is too short to reach the top of the shelf.

--> He is not tall enough to reach the top of the shelf. (tobe too adj for sbd to do sth = isn't adj (trái nghĩa) enough for sbd to do sth)

The river is too dirty for us to swim in

--> The river is not clean enough for us to swim in. (tobe too adj for sbd to do sth = isn't adj (trái nghĩa) enough for sbd to do sth)

Xin ctlhn!

CHÚC BẠN HỌC TỐT

`->` He is not tall enough to reach the top of the shelf. 

`-` tall (cao) >< short (thấp)

`->` The river is not clean enough for us to swim in. 

`-` dirty (bẩn) >< clean (sạch) 

`-` Cấu trúc: S + tobe + too + adj + (for sb) + to V-inf + O: quá...đến nỗi không thể 

`=>` S + tobe + not + adj + enough + (for sb) + to V-inf + O: ko đủ...để làm gì