`15` Jane is not old enough to stay home alone 

`=>` S + be + not + adj + enough + ( for + O ) + to - V  : Ko đủ để làm việc gì đó 

`16` The boy isn't tall enough to reach the shelf 

`=>` S + be + not + adj + so + S + can't + V + O 

`=` S + be + not + adj + enough + ( for + O ) + to - V : Ko đủ để làm việc gì đó 

`17` Are they going home learn Japanese next summer ?  

`=>` Do / Does + S + intend to - V ? : Dự định làm việc gì đó 

`=` Thì tương lai gần : Is / Are / Am + S + going  to + V + O ? 

`18` I am going to buy a laptop 

`=>` S + plan to - V : lên kế hoạch làm việc gì đó

`=` Thì tương lai gần : S + is / are / am + going  to + V + O  

`19` I wasn't helped prepare the presentation 

`=>` Câu bị động thì quá khứ đơn : 

`-` S + was / were + not + Vpp + ( by + O ) 

`20` He has short curly white hair

`=>` Trật tự tính từ : Size : Kích cỡ   ( Short ) `->` Shape : hình dáng  ( curly ) `->` Color : màu sắc ( White ) 

`15.` Jane is not old enough to stay home alone

*Cấu trúc enough: S + be + adj + enough + (for sb) + to + V

`16.` The boy isn't tall enough to reach the shelf

*Cấu trúc enough: S + be + adj + enough + (for sb) + to + V

`17.` Are they going to learn Japanese next summer?

*intend to + V_inf = be going to + V_inf (tương lai gần): dự định, sẽ làm gì

`18.` I am going to buy a new laptop 

*plan to + V_inf = be going to + V_inf (tương lai gần): lên kế hoạch, sẽ là gì

`19.` I wasn't helped to prepare the presentation 

*Cấu trúc bị động thì quá khứ đơn: S + was/ were + (not) + PP + (by O)

`20.` He has short, white and curly hair

*(a/an) + adj + noun

Mà hair (tóc) không đếm được nên không dùng a/ an