1. That girl used to walk around the lake in the evening. (used to + $V{0}$

2. Lan is going to visit her grandparents. (be going to do sth : sẽ làm gì -> việc làm có kế hoạch trước)

3. The house isn't cheap enough for me to buy.

(S + be + adj + enough + (for someone) + to do sth

1. That girl used to walk around the lake in the evening

=>used to + v0

2.Lan is going to visit her grandparents/lan plans to visit her grandparents
=>(be going to= intend to=plan to)

3. The house isn't cheap enough for me to buy

=>S + be(not) + adj + enough + (for someone)+ to do sthing

xin 5s là đc ròi ạ :v