1. They don't use an 's' for the third person singular.
2. They make questions by inversion ('she can go' becomes 'can she go?').
3. They are followed directly by the infinitive of another verb (without 'to').
| Modals | Expressing | Example |
| Must | Strong obligation | You must stop when the traffic lights tur red. |
| Logical conclusion/ certainty | He must be very tired. He has been working all day long. | |
| Must not | Prohibition | You must not smoke in the hospital. |
| Can | Ability | I can swim. |
| Permission | Can I use your phone please? | |
| Possibility | Smoking can cause cancer. | |
| Could | Ability in the past | When I was younger I could run fast. |
| Polite permission | Excuse me, could I just say something? | |
| Possibility | It could rain tomorrow! | |
| May | permission | May I use your phone please? |
| Possibility, probability | It may rain tomorrow! | |
| Might | Polite permission | Might I suggest an idea? |
| Possibility, probability | I might go on holiday to Australia next year. | |
| Ought to | Moral duty/social responsibility | I really ought to phone Mum. |
| Shall | Asking for instruction | Shall I roast or stew it? |
| Should | Instruction | All visitors should report to reception. |
| Need | Immediate necessity (asking permission not to do something) | You needn’t pay for that phone call. |
| Talking about future obligation | We’ll need to buy a new car next year. |
Perfect Modal Verbs
Modal verb +have+past participle
| Could have Couldn’t have | Past ability | The boy could have done the dishes himself but his father decided to help. |
| Should have Shouldn’t have | You did or didn't do something that was a good idea. | The girl shouldn't have spun around so many times. She fell down. |
| would have wouldn't have | past condition /past situation | This house of cards would have fallen over if the person who built it hadn't been so careful. |
| may have may not have | past possibility | My grandfather may have used this camera when he was a young man, but I'm not sure. |
| might have might not have | past possibility | Her mother might have put mustard on her sandwich. She hopes not. |
| must have must not have | past probability/ something probably happened in the past. | They must have practiceda lot because they're very good musicians. |
Unit 7. NON-FINITE FORMS OF THE VERBS
Non-finite verb forms do not show tense, person or number.
There are three types of non-finite verbs: gerunds, infinitives, and participles.
For example,
· I hate camping.
(Camping is a non-finite verb. In fact, it is a gerund, i.e., a noun formed from a verb).
· I want to go there.
(To go is a non-finite verb. It is an infinitive, i.e., the base form of a verb).
· We ate our roasted marshmallows.
(Roasted is a non-finite verb. It is a participle, a type of adjective).
THE INFINITIVE
The infinitive is a verbal form which consists of the base form of the verb with the particle "to": to do; to go; to play; to take; to break; to find.
The infinitive has names an action (to drive a car) or state (to be sick), but cannot show person, number, or mood.
The infinitive active and passive forms (to take; to be taken) and can express voice and time.
The infinitive can have a direct object (He plans to visit a museum) or a prepositional object (He wants to know about it) and can be modified by an adverb (He tried to walk slowly).
The infinitive can be part of the compound verbal predicate (She can drive; We must go) or part of the compound nominal predicate (His aim is to help you).
The infinitive has the following active and passive forms:
| simple | to write |
| continuous | to be writing |
| perfect | to have written |
| perfect continuous | to have been writing |
| simple passive | to be written |
| perfect passive | to have been written |
The examples below illustrate the use of the infinitive forms in sentences.
I asked him to write a report.
He is supposed to be writing a report now.
He appears to have written a report already.
He seems to have been writing a report for two hours already.
I expect his report to be written tomorrow.
I expect his report to have been written by now.
Unit 8. THE GERUND
Gerunds are formed from verbs by adding ING: be – being; go – going; play – playing; talk – talking; write – writing. Gerunds can be formed from most verbs (except modal verbs).
The gerund has the following active and passive forms:
| simple active | asking, writing |
| perfect active | having asked, having written |
| passive | being asked, being written |
| perfect passive | having been asked, having been written |
Asking questions is his hobby. (asking – simple form)
I completely forgot having asked him to wait for me there. (having asked – perfect form)
She doesn't like being asked such questions. (being asked – passive form)
He could not remember ever having been asked to do such a thing. (having been asked – perfect passive form)