1. We used to play soccer badly
=> Often + Ved = used to +V-inf  : diễn tả 1 thói quen trong QK
2. My sister is old enough to drive a car
=>  S + tobe + adj enough + (for sb) + to V-inf
3. They are interested in playing tennis
=> Like + V-ing = be interested in + V-ing : thích làm gì
6. That house is more expensive than this house 
=> So sánh hơn: S1 + V + adj/adv+er  + than + S2 (adj/adv ngắn)
                            S1 + V + more/less +adj/adv +than S2 (adj/adv dài)
7. - Let's watch some sports
=> Let's + V + O
- How about watching some sports
=> How about + V-ing 
- Why don't we watch some sports 
=> Why don't we + V-inf
- We should watch some sports, shouldn't we ?
=> Câu hỏi đuôi (tag question) 
S + V (s,es,ed,2..)...., don't/ doesn't/ didn't+S ?

1. We used to play soccer badly

used + to V_inf

2. My sister isn't old enough to drive a car

*Cấu trúc enough: S + be+ (not) + adj + enough + for sb + to + V

3. They are interested in playing tennis

like + V_ing/ to V_inf = be interested in + V_ing

5. They are interested in planting the flowers

love + V_ing/ to V_inf = be interested in + V_ing

6. That house is more expensive than this house

*Động từ tobe:

→ Đối với tính từ có một âm tiết: $S_{1}$ + be + adj-er + than + $S_{2}$ 

→ Đối với tính từ có từ hai âm tiết trở lên: $S_{1}$ + V + more adj + than + $S_{2}$ 

7. Let's watch some sports

    How about watching some sports?

    Why don't we watch some sports?

    We should watch some sports

*What about + V_ing?

*Let's + V_inf

*How about + V_ing?

*Why don't we + V_inf?

*S + should + V_inf