CHUYấN ĐỀ: CAN/COULD and “BE ABLE TO”
A /Chúng ta dùng can để nói một sự việc có thể xảy ra hay ai đó có khả năng làm được việc gì. Chúng ta dùng can+infinitive (can do/can see… )
1.We can see the lake from our bedroom window.
2.I’m afraid I can’t come to the party on Friday.
B/ (Be) able to… có thể thay thế được cho can (nhưng can vẫn được dùng nhiều hơn)
Are you able to speak any foreign languages?
Nhưng can chỉ có hai dạng can (present) và could (past) nên khi cần thiết chúng ta phải dùng (Be) able to… Hãy so sánh:
I can’t sleep.
Nhưng
I haven’t been able to sleep recently. (can không có present perfect)
Tom can come tomorrow.
Nhưng
Tom might be able to come tomorrow. (can không có infinitive)
C/ Could và was able to…
Đôi khi could là dạng quá khứ của can. Chúng ta dùng could đặc biệt với:see /hear /smell/ taste /feel /remember /understand
1.When we went into the house, we could smell burning.
2.She spoke in a very low voice, but I could understand what she said.
Chúng ta dùng could để diễn tả ai đó là có khả năng nói chung hay được phép để làm điều gì đó.
1.My grandfather could speak five languages.
2.We were completely free. We could do what we wanted. (= we were allowed to do…)
Chúng ta dùng could để chỉ khả năng nói chung (general ability). Nhưng để đề cập tới một sự việc xảy ra trong một tình huống đặc biệt (particular situation), chúng ta dùng was/were able to… (không dùng could)
They didn’t want to come with us at first but we managed to persuade them or were able to persuade them (but not ‘could persuade’)
D/Hãy so sánh:
Jack was an excellent tennis player. He could beat anybody. (= He had the general ability to beat anybody)
Nhưng
Jack and Alf had a game of tennis yesterday. Alf played very well but in the end Jack managed to beat him or was able to beat him (= he managed to beat him in this particular game)
Exercise 1: Complete the following tag questions:
You can’t answer all the question, ………………..?
He believes you, ………………..?
You will help me to do the dishes, ………………..?
The teacher should explain the lesson, ………………..?
The boy didn’t know the lesson, ………………..?
Bob frightened you, ………………..?
You can speak English well, ………………..?
She couldn’t arrange that, ………………..?
You won’t lend him, ………………..?
He shouldn’t do it, ………………..?
She`s very funny. She`s got a great sense of humour, ………………..?
The area was evacuated at once, ………………..?
Mr Smith usually remembered his wife`s birthdays, ………………..?
It never works very well, ………………..?
Neither of them offered to help you, ………………..?
There`ll be plenty for everyone, ………………..?
Grammar 2: Could/ be able to + Vinf
* Chỉ khả năng, năng lực ở hiện tại : can, be able to ; ở quá khứ could, was/ were able to
Tuy nhiên ta thường dùng can/ could trong trường hợp nài.
Ex: 1. He could/ was able to run very fast when he was a boy.
2. We were able to/ could get tickets for the match yesterday.
3. When I was young I could/ was able to climb any tree in the forest.
4. In those day we had a car, so we could/ were able to travel very easily.
* Trong câu có các động từ: see, hear, smell, taste, feel, remember, understand ( Dùng can/ could
Ex: When we went into the house, we could smell burning.
* Trong câu phủ định dùng cả hai đều đúng.
Ex: I come last night, sorry. OR I able to come last night, sorry.
* Diễn đạt những việc làm được vào một dịp nào đó, ta dùng be able to chứ ko ding can/ could
Ex: The fire spread through the building quickly, but everybody was able to escape.
Exercise 2: Complete these sentences with “could, couldn’t” or “was/ were able to”:
A girl fell into the river but fortunately we …………………… rescue her.
I …………………… walk when I was less than a year old.
My grandfather …………………… walk without any help last night.
…………………… you understand what he was saying?
My grandmother …………………… speak Spanish.
Suddenly all the lights went out. We ……………………see a thing.
The computer
nguon VI OLET
