
Explanations
Don't have to and
must not
Should
Could
• Don't have to refers to an absence of obligation. You don't have to work tomorrow.
• Must not refers to an obligation not to do something. You must not leave the room before the end of the test.
Where *should appears, ought to can also be used.
• Expectation This film *should be really good.
• Recommendation
I think you *should talk it over with your parents. In writing, should can be used to express a strong obligation politely.
Guests should vacate their rooms by midday.
• Criticism of an action You *shouldn't eat so much late at night.
• Uncertainty Should I leave these papers on your desk?
• Should and verbs of thinking Should is often used with verbs of thinking, to make an opinion less direct.
I should think that model would sell quite well.
• With be and adjectives describing chance This group of adjectives includes odd, strange, funny (=odd) and the expression
What a coincidence.
It's strange that you should be staying in the same hotel!
• After in case to emphasise unlikelihood I'm taking an umbrella in case it should rain. See Grammar 8 for similar uses in conditional sentences.
• Could is used to express possibility or uncertainty. This could be the house.
• Could is used with comparative adjectives to express possibility or impossibility.
The situation couldn't be worse. It could be better.
65 2
A D V A N C E D L A N G U A G E P R A C T I C E
Can
Must and can't
May and might
Shall
Will
• Could is used to make suggestions. We could go to that new restaurant opposite the cinema.
• Could is used to express unwillingness. / couldn't possibly leave Tim here on his own.
• Can with be is used to make criticisms. You can be really annoying, you know!
• Can is also used with be to refer to capability. Winter here can be really cold.
These refer to present time only. (See bound to). In expressing certainty, they are opposites.
This must be our stop. (I'm sure it is.) This can't be our stop. (I'm sure it isn't.)
• May can be used to express although clauses: She may be the boss, but that is no excuse for shouting like that. See also Grammar 14 Emphasis.
• May/might as well This describes the only thing left to do, something which the speaker is not enthusiastic about.
Nobody else is going to turn up now for the lesson, so you may as well go home.
• May and might both express possibility or uncertainty. May is more common in formal language.
The peace conference may find a solution to the problem.
• There is an idiomatic expression with try, using may for present reference, and might for past reference.
Try as I might, I could not pass my driving test. (This means although I tried hard, I could not pass my driving test.)
• Shall can be used with all persons to emphasise something which the speaker feels is certain to happen or wants to happen.
/ shall definitely give up smoking this year.
We shall win! (shall is stressed in this sentence)
• Similarly, shall is used in formal rules and regulations. No player shall knowingly pick up or move the ball of another player.
• Will can be used to express an assumption. A: The phone's ringing. B: That'll be for me.
66 3
Trên đây là phần đầu tài liệu — bấm Đọc sách để xem đầy đủ.