`1`. It was easy for this home robot to cook meals.

This home robot could cook meals

- S + could/couldn't + V(infi) 

`2`. Teacher robots can teach all subjects in the future.

Teacher robots will be able to teach all subjects in the future

- Thì tương lai đơn

- Be able to + V: Có thể làm gì 

`3`. Doctor robots don't know how to do household chores.

Doctor robots can't do the household chores

- S + can/can't + V(infi)

`4`. I don't think robots will be able to play football as we do.

The robot won't be able to play football as we do

- Thì tương lai đơn

- Be able to + V : Có thể làm gì

`1`.This home robot could cook meals

`\rightarrow` S + could / couldn't + V-inf : Có thể / Không thể làm gì [ Dạng Quá khứ ]

`2`.Teacher robots will be able to teach all subjects in the future

`\rightarrow` Thì TLĐ ( ĐT Tobe ) : S + will be + adj / n ( `2 , 4` )

`\rightarrow` be able + to do sth : Có thể làm gì ( `2 , 4` )

`3`.Doctor robots can't do the household chores

`\rightarrow` S + can / can + V-inf : Có thể / Không thể làm gì

`4`.Robots won't be able to play football like we do

`\text{# TF}`