have only one form which is not changed in reported speech. They are very much alike in meaning and they are nearly always interchangeable. Should is followed by the infinitive without the particle “to”, ought is followed by the infinitive with the particle “to”. These modal verbs express:

1. MODAL OBLIGATION OR DUTY which may not be fulfilled. (in all kinds of sentences)

Should + Non-Perfect Infinitive refers the action to the present or future.

Ought + Non-perfect Infinitive refers the action to the present or future.

You ought to/should help your friend. He is in trouble.

Ought she to help him? Should she help him?

He oughtn’t to/shouldn’t do it.

Should/ought to + Perfect Infinitive shows that a desirable action was not fulfilled and implies reproach, criticism, regret.

You ought to/should have told me about it.

Shouldn’t/oughtn’t to + Perfect Infinitive shows that an undesirable was fulfilled, something wrong has been done and it is now too late to change it (= criticism of the past action).

You oughtn’t to/shouldn’t have interfered.

2. ADVISABILITY, DESIREABILITY (in all kinds of sentences, usually with Non-Perfect Infinitive)

You ought to see a doctor.

You should not read in bed at all.

Note: It is sometimes difficult to discriminate between the first and the second meaning.

Synonyms: I advise you to do…; I advise you not to do…; I recommend you to do…; I urge you to do…; It’s advisable for you to do…; I would advise you to do…

3. PROBABILITY, something naturally expected (in the affirmative and negative sentences, generally with the Indefinite Infinitive)

This dish ought to/should be very delicious as it has been prepared by Mother.

This dish is very delicious. It ought to/should have been prepared by Mother.

The guests shouldn’t come for another hour. (Гості навряд чи прийдуть раніше, ніж через годину.)

Note: Must is more frequent in this meaning than should/ought to.


1) INSTRUCTIONS and CORRECTIONS (in all kinds of sentences with the Indefinite Infinitive)

You should use the definite article in this sentence.

You should take this medicine three times a day before your meals.

2) for EMOTIONAL COLOURING (with the Indefinite Infinitive) in the following cases:

a) in rhetorical questions beginning with “why”:

Why should I help him?

Why shouldn’t I join them?

b) in object clauses beginning with “why”:

I could not understand why he should be angry with us.

I don’t see why we shouldn’t make friends.

c) in attributive appositive clauses beginning with “why” after the noun “reason”:

There is no reason why they shouldn’t get on well together.

I don’t see any reason why he shouldn’t be happy.

d) in construction of the following kind:

The door opened and who should come in but Tom.

As I was crossing the street, whom should I meet but Aunt Ann herself.

e)in the set phrase: How should I know?


“Will” is not purely modal verb. It almost always combines its modal meaning with the function of the auxiliary verb of the future tense. “Will” has 2 forms: will – for the present tense, would – for the past tense. The use of the forms will and would is mainly parallel, though in a few cases their meanings differ.

I. Will/would followed by the Indefinite Infinitive may express:

1. VOLITION (willingness, intention, determination, readiness). (in affirmative and negative sentences)

Synonyms: I intend…; I am willing…; We wish…, We want…; I am determined…

I have often spoken at public meetings but this time I won’t.

I said I would go there by all means.

This meaning is often found in conditional sentences, that is in complex sentences with subordinate adverbial clauses of condition:

If you will wait for me, I’ll be very grateful.

If you would help me with my work I shouldn’t worry about it.

2. PERSISTENCE (or RESISTANCE, INSISTENCE), REFUSAL TO PERFORM AN ACTION (also with lifeless thing; in affirmative and negative sentences)

Synonyms: Somebody insists on…; keeps on…; refuses…; continues…;

The teacher scolds her for whispering at the lesson, but she will whisper.

The door won’t (wouldn’t) open.

3. HABITUAL or RECURRENT ACTIONS (in affirmative sentences)

Synonym: used to

will (the present tense) – is not common.

would (the past tense) – is mainly characteristic of literary style.

That romantic girl will sit staring at the night sky.

He would fish for hours without catching anything.

4. POLITE REQUEST, OFFERS, INVITATIONS (sentence with would renders a greater degree of politeness)

Will you pass me the salt?

Would you like to come to tea this afternoon?

5. COMMAND (only will)

You will do exactly as I say.

An impatient command can begin with “will you”:

Will you be quiet!

“Will you” is used in the tag after: a) a negative command (Don’t be late, will you.); b) a positive command (Shut the door, will you.)


What will be will be.

Accidents will happen. (Нещасні випадки неминучі.)

Truth will out. (Істину не приховати.)

That’s exactly like Jocelyn – she would lose the key.

6. LOGICAL NECESSITY or EXPECTATION (mainly “would’); (in affirmative and negative sentences)

You would forget. – Звичайно ж, ви забули.

You would be late! - Звичайно, ти знову запізнився.

II. Will/would followed by any form of the Infinitivecan express supposition, probability, prediction, certainty(in the similar way to “must”); (in affirmative and negative sentences); (“would” is more hesitant)

Who is the man? You wouldn’t know him.

John will/would still be reading his paper.

You will/would have heard that the plan is to be discussed tomorrow.