Unit3 :

Grammar 2:                                                                              Modals 

1.      Definition :

Modals (also called modal verbs, modal auxiliary verbs, modal auxiliaries) are special verbs which behave irregularly in English. They are different from normal verbs like "work, play, visit..." They give additional information about the function of the main verb that follows it. They have a great variety of communicative functions.

Modal verbs are followed by an infinitive without "to", also called the bare infinitive.

Examples:

§  You must stop when the traffic lights turn red.

§  You should see to the doctor.

§  There are a lot of tomatoes in the fridge. You need not buy any.

2.      Characteristics of modal verbs:

§  they never change their form. You can't add "s", "ed", "ing"...

§  They are always followed by an infinitive without "to" (e.i. the bare infinitive.)

§  They are used to indicate modality allow speakers to express certainty, possibility, willingness, obligation, necessity, ability

3.      List of modal verbs :

Modal Verb	Expressing	Example
must	Strong obligation	You must stop when the traffic lights turn red.
	logical conclusion / Certainty	He must be very tired. He's 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.
need not	lack of necessity/absence of obligation	I need not buy tomatoes. There are plenty of tomatoes in the fridge.
should/ought to	50 % obligation	I should / ought to see a doctor. I have a terrible headache.
	advice	You should / ought to revise your lessons
	logical conclusion	He should / ought to be very tired. He's been working all day long.
had better	advice	You 'd better revise your lessons

 

II)              Modals in the present and past:

Generally speaking modals in the past have the following form:

§  modal + have + past participle

Example:

§  Present: You should see a doctor.

§  Past: You should have seen a doctor

Except for modals that express obligation,ability and lack of necessity:

§  Obligation: Present = I must / have to work hard. -- Past = I had to work hard.

§  Ability: Present = I can run fast. -- Past = I could run fast when I was young.

§  Lack of necessity: Present = You don't have to / needn't take your umbrella. -- Past = You didn't have to / didn't need to take your umbrella.

	Modals in the Present	Modals in the Past
Obligation	You must / have to stop when the traffic lights are red.	You had to stop.
Advice	You should see a doctor.	You should have seen a doctor
Prohibition	You mustn't smoke here.	You mustn't have smoked there.
Ability	I can run fast.	I could run fast. now I am old.
Certainty	He has a Rolls Royce. He must be very rich. He can't be American. His English is terrible.	He must have been rich. He had a big house and an expensive car. He can't have written that poem. He was illiterate.
Permission	Can I go out?	She could drive her father's car when she was only 15.
Possibility	It may / can / could / might rain. It's cloudy.	I guess it may / can / could / might have been Lacy on the phone.
Lack of necessity	You don't have to / needn't buy any tomatoes. There are plenty in the fridge.	You didn't have to / didn't need to buy tomatoes.