Bài 12: Thể khiếm khuyết - Modals (Phần 2)

 Cách dùng động từ khiếm khuyết trong quá khứ:

- Diễn tả một khả năng, năng lực

- Thể hiện mức độ chắc chắn

- Thể hiện một trách nhiệm, nhiệm vụ

- Nêu quan điểm hay lời khuyên

Bài 12: MODALS (PHẦN 2)

Contents
- Past ability
- Certainty & Uncertainty
- Obligation
- Opinions & Advice

Past ability
Could(n't) & was(n't) able to
- Peter could swim/ was able to swim when he was ten.

Specific past action
- When Jane fell in the river, David was able to rescue her.

- The boy was only 3 years, but he was able to help his mother do housework.

Certainty & Uncertainty
Modal + have + past participle
- You must have left your passport on the plane.
- She must have been really tired after the party last night.

- Lina can't have written this.
- I can't have ticked the wrong answer! No!

- Maria might/may/could have taken the bus. (Perhaps she did.)
- Well, Peter could may have bought a ticket for you.

Obligation
Had to, didn't have to, didn't need to, needn't have done
- There was a sports competition at my school yesterday. Only the players had to come. I wasn't a player so I didn't have to be there.

- Although I didn't need to attend the match, I thought my friends would need more support. When I came, there were already too many supporters. I felt useless, so I left. I needn't have come.

Opinions & Advice
Should have + V3
- I didn't work hard enough, so I failed the test. I should have worked harder.

- You shouldn't have eaten so much! You're like a fat pig!

In the test
1. There were almost 200 questions to be done in 60 minutes. However, Tom ________ finish on time.
A. could
B. was able to
C. wasn't able to
D. couldn't
2. I know Tom. He ________ told a lie. He's an honest student.
A. can't have
B. could have
C. must have
D. should have