21 The film was not interesting enough to watch till the end

_ S + be + adj + enough ( for smb) + to V

22 The house on the corner is too expensive for us to buy

_ S + be + too adj (for smb) + to V 

23 I spend one hour and a half driving my childrenn to school.

_ It + take(s) + time + to V = S + spend + time + VIng : mất bao nhiêu thời gian để làm gì

`21`. The film was not interesting enough to watch till the end.

`->` Cấu trúc "enough": S + be + adj + enough + (for SO) + to V

`22`. The house on the corner is too expensive for us to buy.

`->` Cấu trúc "too ... to": S + be + too + adj + for SO + to V

`23`. I spend on hour and a half driving my children to school.

`->` S + spend + thời gian + Ving = It + takes + SO + thời gian + to V