ĐỘNG từ KHUYẾT THIẾU lý thuyết và bài tập

Bạn đang xem bản rút gọn của tài liệu. Xem và tải ngay bản đầy đủ của tài liệu tại đây (710.66 KB, 36 trang )

Lý thuyết và bài tập
Chuyên đề: ĐỘNG TỪ KHUYẾT THIẾU
A. LÝ THUYẾT CHUNG
I. KHÁI NIỆM
- Gồm can, could, may, might, must, ought, had better, will, would, shall,
should
- + V nguyên thể
- Chỉ khả năng, sự chắc chắn, sự cho phép, nghĩa vụ…
Lưu ý:
- Không có TO ở nguyên mẫu và không có TO khi có động từ theo sau.
They can speak French and English.
- Không có S ở ngôi thứ ba số ít thì Hiện tại.
He can use our phone.
- Chỉ có nhiều nhất là 2 thì: Thì Hiện tại và thì Quá khứ đơn.
She can cook meals.
She could cook meals when she was twelve.
Trong những trường hợp khác ta sử dụng những động từ tương đương.

II. PHÂN LOẠI
1. CAN
CAN là một động từ khuyết thiếu, nó chỉ có 2 thì Hiện tại và Quá khứ
đơn. Những hình thức khác ta dùng động từ tương đương be able to.
CAN cũng có thể được dùng như một trợ động từ để hình thành một số
cách nói riêng.

 CAN và COULD có nghĩa là “có thể”, diễn tả một khả năng
(ability).
Can you swim?
She could ride a bicycle when she was five years old.
 Trong văn nói (colloquial speech), CAN được dùng thay cho MAY

để diễn tả một sự cho phép (permission) và thể phủ định CANNOT
được dùng để diễn tả một sự cấm đoán (prohibition).
In London buses you can smoke on the upper deck, but you can’t smoke
downstairs.

 CAN cũng diễn tả một điều có thể xảy đến (possibility). Trong câu
hỏi và câu cảm thán CAN có nghĩa là ‘Is it possible...?’
Can it be true?
It surely can’t be four o’clock already!

 CANNOT được dùng để diễn tả một điều khó có thể xảy ra (virtual
impossibility).
He can’t have missed the way. I explained the route carefully.
 Khi dùng với động từ tri giác (verbs of perception) CAN cho một ý
nghĩa tương đương với thì tiếp diễn.

Listen! I think I can hear the sound of the sea. (không dùng I am hearing)

2. COULD

 COULD là thì quá khứ đơn của CAN.
She could swim when she was five.

 COULD còn được dùng trong câu điều kiện.
If you tried, you could do that work.

 Trong cách nói thân mật, COULD được xem như nhiều tính chất
lịch sự hơn CAN.
Can you change a 20-dollar note for me, please?

Could you tell me the right time, please?

 COULD được dùng để diển tả một sự ngờ vực hay một lời phản
kháng nhẹ nhàng.
His story could be true, but I hardly think it is.
I could do the job today, but I’d rather put it off until tomorrow.

 COULD – WAS/WERE ABLE TO
a) Nếu hành động diễn tả một khả năng, một kiến thức, COULD được
dùng thường hơn WAS/WERE ABLE TO.
He hurt his foot, and he couldn’t play in the match.
The door was locked, and I couldn’t open it.

b) Nếu câu nói hàm ý một sự thành công trong việc thực hiện hành động
(succeeded in doing) thì WAS/WERE ABLE TO được sử dụng chứ
không phải COULD.
I finished my work early and so was able to go to the pub with my
friends.

3. MAY/ MIGHT

 MAY và dạng quá khứ MIGHT diễn tả sự xin phép, cho phép
(permission).
May I take this book? – Yes, you may.
She asked if she might go to the party
 MAY/MIGHT dùng diễn tả một khả năng có thể xảy ra hay không
thể xảy ra.
It may rain.
He admitted that the news might be true.

 Dùng trong câu cảm thán MAY/MIGHT diễn tả một lời cầu chúc.
May all your dreams come true!

 MAY/MIGHT dùng trong mệnh đề theo sau các động từ hope (hy
vọng) và trust (tin tưởng).
I trust (hope) that you may find this plan to your satisfaction.
He trust (hoped) that we might find the plan to our satisfaction.

 MAY/MIGHT dùng thay cho một mệnh đề trạng ngữ chỉ sự nhượng
bộ (adverb clauses of concession).

He may be poor, but he is honest. (Though he is poor...)
Try as he may, he will not pass the examination. (Though he tries hard...)
Try as he might, he could not pass the examination. (Though he tried
hard...)

 MAY/MIGHT thường được dùng trong mệnh đề trạng ngữ chỉ mục
đích (adverb clauses of purpose). Trong trường hợp này người ta
cũng thường dùng CAN/COULD để thay cho MAY/MIGHT.
She was studying so that she might read English books.

 MIGHT (không dùng MAY) đôi khi được dùng trong câu để diễn
tả một lời trách mắng có tính hờn dỗi (petulant reproach)
You might listen when I am talking to you.
(Làm ơn ráng mà lắng nghe tôi nói)
You might try to be a little more helpful.
(Làm ơn ráng mà tỏ ra có ích một chút)

 Trong trường hợp cần thiết người ta dùng be allowed to, permit...
tùy theo ý nghĩa cần diễn tả để thay cho MAY và MIGHT.
I shall be allowed to go to the party.

4. MUST

 MUST là một động từ khuyết thiếu và chỉ có hình thức hiện tại.
 MUST có nghĩa là “phải” diễn tả một mệnh lệnh hay một sự bắt
buộc.
You must drive on the left in London.

 MUST bao hàm một kết luận đương nhiên, một cách giải thích duy
nhất hợp lý theo ý nghĩ của người nói.
Are you going home at midnight? You must be mad!
You have worked hard all day; you must be tired.

 MUST NOT (MUSTN’T) diễn tả một lệnh cấm.
You mustn’t walk on the grass.

 Khi muốn diễn tả thể phủ định của MUST với ý nghĩa “không cần
thiết” người ta sử dụng NEED NOT (NEEDN’T).
Must I do it now? – No, you needn’t. Tomorrow will be soon enough.
 CANNOT (CAN’T) được dùng làm phủ định của MUST khi MUST
diễn tả ý nghĩa kết luận đương nhiên, một cách giải thích duy nhất
hợp lý theo ý nghĩ của người nói như đã đề cập trong điểm 2 trên
đây.
If he said that, he must be mistaken.
If he said that, he can’t be telling the truth.

 MUST và HAVE TO
a) HAVE TO dùng thay cho MUST trong những hình thức mà MUST
không có.
We shall have to hurry if we are going to catch the twelve o’clock train.
b) HAVE TO không thể thay thế MUST khi MUST mang ý nghĩa kết
luận đương nhiên, một cách giải thích duy nhất hợp lý theo ý nghĩ của
người nói như đã đề cập trong điểm 2 trên đây. Người ta phải diễn tả
bằng những cách khác.
He must be mad. (I personally thought that he was mad)

c) MUST và HAVE TO đều có thể dùng để diễn tả sự cưỡng bách, bắt
buộc
(compulsion). Tuy nhiên MUST mang ý nghĩa sự cưỡng bách đến từ
người nói trong khi HAVE TO mang ý nghĩa sự cưỡng bách đến từ hoàn
cảnh bên ngoài (external circumstances)
You must do what I tell you.
Passengers must cross the line by the bridge. (Lệnh của Cục Đường Sắt)
Passengers have to cross the line by the bridge. (Vì không còn đường nào
khác)

5. SHALL/ SHOULD

 SHALL có thể là:
- Một trợ động từ giúp hình thành thì Tương lai (Simple Future) ở ngôi
thứ nhất số ít.
I shall do what I like.
- Một động từ khuyết thiếu. Khi là động từ khuyết thiếu SHALL diễn tả
một lời hứa (promise), một sự quả quyết (determination) hay một mối đe
dọa (threat) theo ý nghĩ của người nói.

If you work hard, you shall have a holiday on Saturday. (promise)
He shall suffer for this; he shall pay you what he owes you. (threat)
These people want to buy my house, but they shan’t have it.
(determination)

 SHOULD được dùng trong những trường hợp sau:

- Làm một động từ khuyết thiếu có nghĩa là “nên” và tương đương với
ought to.
You should do what the teacher tells you.
People who live in glass houses should not throw stones. (proverb)
- Dùng thay cho must khi không muốn diễn tả một ý nghĩa quá bắt buộc
với must.
Members who want tickets for the dance should apply before September
1st to the Secretary.

6. WILL/ WOULD

 WILL có thể là:
- Một trợ động từ. Dùng làm trợ động từ WILL giúp hình thành thì
Tương lai (simple future).
- Một động từ khuyết thiếu. Khi là một động từ khuyết thiếu WILL diễn
tả một sự mong muốn (willingness), một lời hứa (promise) hay một sự
quả quyết (determination).
All right; I will pay you at the rate you ask. (willingness)
I won’t forget little Margaret’s birthday. I will send her a present.
(promise)
- Trong cách diễn tả sự quả quyết (determination) cả SHALL lẫn WILL
đều có thể sử dụng nhưng mỗi từ mang một nghĩa riêng. Với SHALL, sự

quả quyết là ở người nói.
- Với WILL, sự quả quyết ở chủ từ (subject) của động từ. So sánh hai thí
dụ sau:

(a) George shall go out without his overcoat.
(b) George will go out without his overcoat.
Ở câu (a), người nói nhất định bắt George phải đi ra ngoài mà không
được mặc áo khoác.
Ở câu (b) George nhất định đi ra ngoài mà không thèm mặc áo khoác.

 WOULD có thể là:
- Một trợ động từ. WOULD giúp hình thành một Tương lai trong quá khứ
(future in the past) hay các thì trong câu điều kiện.
He said he would send it to me, but he didn’t.
If she were here, she would help us.
He would have been very happy if he had known about it.
- Khi dùng như một động từ khuyết thiếu, WOULD diễn tả một thói quen
trong quá khứ.
Với nghĩa này, WOULD có thể dùng thay cho used to.
Every day he would get up at six o’clock and light the fire.

7. OUGHT TO – DARE – NEED
a/ OUGHT TO

 OUGHT TO là mộ
t độ
ng từ khuyết thiếu chỉ có thì Hiệ
n tại (simple
present). Nó có nghĩa là “nên”, gần giống với should. Trong hầu

hết các trường hợp OUGHT TO có thể được thay thế bằng should.
They ought to (should) pay the money.

He ought to (should) be ashamed of himself.

 OUGHT TO cũng dùng để diễn tả mộ
t sự gần đúng, rất có thể
đúng (strong probability).
If Alice left home at 9:00, she ought to be here any minute now.

 OUGHT TO có thể dùng trong tương lai với các từ xác định thời
gian tương lai như tomorrow, next Tuesday...
Our team ought to win the match tomorrow.

 OUGHT NOT TO HAVE + past participle diễn tả mộ
t sự khô
ng
tán đồng về mộ
t hành độ
ng đã làm trong quá khứ.
You ought not to have spent all that money on such a thing.

b/ DARE

 DARE có nghĩa là “dám, cả gan” có thể được xem như mộ
t độ
ng
từ khuyết lẫn độ
ng từ thường. Khi là mộ

t độ
ng từ khuyết thiếu, nó
có đầy đủ đặ
c tính của loại độ
ng từ này.
You daren’t climb that tree, dare you? (động từ khuyết thiếu)
He doesn’t dare to answer my letter. (động từ thường)
She didn’t dare to say a word, did she? (động từ thường)

 Thành ngữ I daresay có nghĩa là “có thể, có lẽ” đồng nghĩa với
các từ perhaps, it is probable. Thành ngữ này thường khô
ng dùng
với chủ từ nào khác ngoài ngô
i thứ nhất.
He is not here yet, but I daresay he will come later.
c/ NEED

 Có hai độ
ng từ NEED: mộ
t độ
ng từ thường và mộ
t độ
ng từ khuyết
thiếu. Khi là độ
ng từ khuyết thiếu NEED chỉ có hình thức Hiệ
n tại
và có đầy đủ đặ
c tính của mộ
t độ

ng từ khuyết thiếu. Nó có nghĩa là
“cần phải”, tương tự như have to. Vì thế nó cũng được xem là mộ
t
loại phủ định của must.
Need he work so hard?
You needn’t go yet, need you?

 Có mộ
t điều cần nhớ là độ
ng từ khuyết thiếu NEED khô
ng dùng ở
thể xác định. Nó chỉ được dùng ở thể phủ định và nghi vấn. Khi
dùng ở thể xác định nó phải được dùng với mộ
t từ ngữ phủ định.
You needn’t see him, but I must.
I hardly need say how much I enjoyed the holiday.
8. USED TO

 USED TO là mộ
t hình thức độ
ng từ đặ
c biệ
t. Nó có thể được xem
như mộ
t độ
ng từ thường hay mộ
t độ
ng từ khuyết thiếu trong việ
c
hình thành thể phủ định và thể nghi vấn.

You used to live in London, usedn’t you?
He usedn’t to smoke as much as he does now.
He didn’t use to smoke as much as he does now.
Did you use to climb the old tree in the garden?

 Ngày nay người ta có khuynh hướng dùng did và didn’t để lậ
p thể
phủ định và thể nghi vấn cho USED TO. Trong nhiều trường hợp
thể phủ định có thể được hình thành bằng cách sử dụng never.

You never used to make that mistake.

 USED TO được dùng để chỉ mộ
t hành độ
ng liên tục, kéo dài, lặ
p đi
lặ
p lại trong quá khứ mà nay khô
ng còn nữa.
People used to think that the earth was flat.

 Với thì Quá khứ đơn người ta chỉ biết hành độ
ng đã xảy ra. Với
USED TO người ta thấy được tính chất kéo dài của hành độ
ng ấy.
He was my classmate. (không rõ trong thời gian bao lâu)
He used to be my classmate. (trong mộtt thời gian khá lâu)

 Phâ

n biệ
t USED TO và mộ
t số hình thức khác
1. USED TO + infinitive: hành độ
ng liên tục trong quá khứ
2. (be) USED TO + V.ing: quen với một việc gì
3. (get) USED TO + V.ing: làm quen với một việc gì.
He used to work six days a week. (Now he doesn’t)
It took my brother two weeks to get used to working at night. Now he’s
used to it.

Biến thể của trợ động từ tình thái (động từ khuyết thiếu)
Bản thân các động từ khuyết thiếu có thể tồn tại ở dạng thức khác (dùng
từ khác)
Nhưng nghĩa không thay đổi. Các e cần lưu ý để diễn đạt đúng ý, dịch
chuẩn ngữ nghĩa.

Modal
Verb

Substitute

must

to have to

Example
I must swim. = I have to swim.

must not not to be allowed to

I must not swim. = I am not allowed to
swim.

can

to be able to

I can swim. = I am able to swim.

may

to be allowed to

I may swim. = I am allowed to swim.

need

to have to

I need to swim. = I have to swim.

need not

Trợ độ
ng từ + not +
have to

I need not swim. = I don't have to swim.

shall /
should/
ought to

to be supposed to / to be I shall / should / ought to swim. = I am
expected to / to be to
supposed to swim. / I am expected to
swim. / I am to swim.

will

Be going to

I will go swimming = I am going to go
swimming.

III. MODAL PERFECT
1. Could, may, might + have + P2 = có lẽ đã
- Diễn đạt một điều gì đó có thể đã xảy ra hoặc có thể đúng ở quá khứ
song người nói không dám chắc.
VD: He could have forgotten the ticket for the concert last night.
(Tối qua, anh ấy có lẽ đã để quên vé cho buổi hòa nhạc.)
I didn’t hear the telephone ring, I might have been sleeping at that time.

(Tôi đã không nghe thấy chuông điện thoại, lúc đó có lẽ tôi đã ngủ.)
John might have gone to the movies yesterday.
(John có lẽ đã đi xem phim ngày hôm qua.)
- Diễn đạt điều gì đó có thể xảy ra nhưng đã không xảy ra

VD: Why did you leave him come home alone? He might/could have got
lost.
(Sao anh lại để nó đi về nhà một mình? Nó có thể đã bị lạc) → sự thật là
nó không bị lạc
2. Should + have + P2 = lẽ ra phải, lẽ ra nên
- Chỉ một việc lẽ ra đã phải xảy ra trong quá khứ nhưng vì lí do nào đó
lại không xảy ra.
VD: Maria should have called John last night.
(Lẽ ra tối qua Maria nên gọi cho John.) → nhưng cô ấy đã không gọi
John should have gone to the post office this morning.
(Sáng nay John lẽ ra phải đến bưu điện) → nhưng anh ta đã không đến
The policeman should have made a report about the burglary.
(Cảnh sát lẽ ra nên viết báo cáo về vụ cướp đó.) → nhưng họ đã không
làm
Chúng ta cũng có thể dùng cụm từ was/were supposed to + V để thay cho
should + have +P2
VD: John was supposed to go to the post office this morning.
The policeman was supposed to make a report about the burglary.

3. Must + have + P2 = chắc là đã, hẳn là đã
- Chỉ một kết luận logic dựa trên những hiện tượng có đã xảy ra ở quá
khứ
VD: The grass is wet. It must have rained last night.
(Cỏ bị ướt. Chắc hẳn tối qua đã có mưa)
Jane did very well on the exam. She must have studied hard.
(Jane đã làm bài kiểm tra rất tốt. Cô ấy chắc hẳn đã học chăm chỉ.)
4. Would + have + Past Participle: (đã . . . rồi) dùng trong câu điều
kiện loại III.
VD: If I had had enough money, I would have bought that Honda.

(Nếu tôi có đủ tiền, tôi đã mua chiếc xe Honda ấy.)
5. Can’t + have + Past Participle: dùng để chỉ một sự việc gần như
chắc chắn không thể xảy ra.
VD: Last night, Mary can’t have gone out with John because she had to
be at home to do her homework.
(Tối qua, Mary không thể đi chơi với John được vì cô ấy phải ở nhà làm
bài tập.)

B. LUYỆN TẬP
Bài 1:
a/ For each situation write a sentence with should or shouldn’t + the
following
go away for a few days

go to bed so late

Put some pictures on the walls
much

take a photograph

1 Liz needs a change.
 She should go away for a few days She should go away for a few days
2 Your salary is very low.
 She should go away for a few days You ________________________
3 Jack always has difficulty getting up
 She should go away for a few days He ________________________
4 What a beautiful view!
 She should go away for a few days You ________________________

5 Sue drives everywhere. She never walks.
 She should go away for a few days She________________________
6 Bill’s room isn’t very interesting.
 She should go away for a few days ________________________

look for another job
use her car so

b/ Read the situations and write sentences with I think/I don’t think /...
should
1 Peter and Cathy are planning to get married. You think it’s a bad idea.
 She should go away for a few days I don’t think they should get married.
2 Jane has a bad cold but plans to go out this evening. You don’t think
this is a good idea. You say to her:
- She should go away for a few days _______________________________________________________
3 Peter needs a job. He’s just seen an advertisement for a job which you
think would be ideal for him, but he’s not sure whether to apply or not.
You say to him:
 She should go away for a few days I think ____________________________________________________
4 The government wants to increase taxes, but don’t think this is a good
idea.
 She should go away for a few days ____________________________________________________
c/ Complete the sentences with should + the verb in brackets
1 Diane should pass the exam. She’s been studying very hard (pass)
 She should go away for a few days ____________________________________________________
2 You missed a great party last night. You should have come. (come)
 She should go away for a few days ____________________________________________________
3 We don’t see you enough. You .... and see us more often (come)
 She should go away for a few days ____________________________________________________

4 I’m in a difficult position. What do you think I .... ?(do)

 She should go away for a few days ____________________________________________________
5 I’m sorry that I didn’t take your advice. I .... wath you said (do)
 She should go away for a few days ____________________________________________________
6 I’m playing tennis with Jane tomorrow. She .... - she's much better than
me (win)
 She should go away for a few days ____________________________________________________
7 We lost the match but we ..... We were the better team. (win)
 She should go away for a few days ____________________________________________________
8 "Is Mike here yet?" "Not yet, but he .... here soon." (be)
 She should go away for a few days ____________________________________________________
9 I posted the letter three days ago, so it .... by now (arrive)
 She should go away for a few days ____________________________________________________
d/ Read the situations and write sentences with should/shouldn’t. Some of
the sentences are past and some are present.
1 I’m feeling sick. I ate too much. I shouldn’t have eaten so much.
 She should go away for a few days ____________________________________________________
2 That man on the motorbike isn’t wearing a helmet. That’s dangerous.
He should be wearing a Helmet
 She should go away for a few days ____________________________________________________
3 When we got to the restaurant, there were no free tables. We hadn’t
reserved one.

 She should go away for a few days We ____________________________________________________
4 The notice says that the shop is open every day from 8.30. It is 9
o’clock now but the shop isn’t open yet.
 She should go away for a few days ____________________________________________________

5 The speed limit is 30 miles an hour, but Kate is doing 50.
 She should go away for a few days She ____________________________________________________
6 Laura gave me her address, but I didn’t write it down. Now I can’t
remember it.
 She should go away for a few days I ____________________________________________________
7 I was driving behind another car. Suddenly the driver in front stopped
without and I drove into the back of his car. It wasn’t my fault.
 She should go away for a few days The driver in front
____________________________________________
8 I walked into a wall.I was looking behind me. I wasn’t looking where I
was going.
 She should go away for a few days ____________________________________________________
Bài 2:
a/ Put in must or can't
1 You've been travelling all day. You must be tired.
2 That restaurant ............. be very good. It's always full of people.
3 That restaurant ……….... be very good. It's always empty.

4 I'm sure I gave you the key. You ………….. have it. Have you looked
in your bag?
5 You're going on holiday next week. You ………….. be looking
forward to it.
6 It rained every day during their holiday so they …………….. have had
a very nice time.
7 Congratulations on passing your exam You ……………... be very
pleased.
8 You got here very quickly. You ……………... have walked very fast.
9 Bill and Sue always travel business class so they …………….... be
short of money.

b/ Put in must or can't
1 You've been travelling all day. You must be tired.
2 That restaurant ………….... be very good. It's always full of people.
3 That restaurant ....................... be very good. It's always empty.
4 I'm sure I gave you the key. You ………………... have it. Have you
looked in your bag?
5 You're going on holiday next week. You ..................... be looking
forward to it.
6 It rained every day during their holiday so they ……………... have had
a very nice time.
7 Congratulations on passing your exam You ........................ be very
pleased.

ĐỘNG từ KHUYẾT THIẾU lý thuyết và bài tập

Tài liệu liên quan

Tài liệu bạn tìm kiếm đã sẵn sàng tải về