MODAL AUXILIARIES

 

FORM: ·        It is used without DO / DON’T, DID / DIDN’T; ·        It is used without TO – Infinitive (Modal + Verb);               Exception: ought to (That ought to be true) ·        NO ‘s’ or ‘es’ in the 3rd person singular.

 

 

CAN is used:

1.    to ask for permission in an informal way:

        Can I open the door?

 

2.    to express possibility or impossibility (with comparative adjectives):

        The Situation couldn’t be worse.

 

3.    to make criticism (with to be):

You can be really annoying, you know!

 

4.    to refer to capability (with to be):

Winter here can be really cold.

5.    to express certainty (in the negative):

This can’t be our stop. (I’m sure it isn’t.)

 

     5. Capability in the future: will be able to

     We’ll be able to have a quicker access to the Internet in a few months.

 

 

 

        Compare:

It’ll be possible to see you on Friday

I’ll be able to see you on Friday

 

CAN °  WILL BE ABLE TO

° I’ll be able to pass my driving test after I’ve had a few lessons.

( WILL BE ABLE TO predicts future achievement )

 

° I can see you tomorrow if you’re free.

(CAN can refer to the future in the sense of ‘be free to’; WILL BE ABLE TO is also possible here, but emphasizes practicality )

 

 

CAN ° COULD

Can/Could I use your car tomorrow please?(could is more polite, or expresses greater uncertainty; can antecipates the answer yes)

 

COULD is used:

1.    to express possibility or uncertainty:

° This could be the house.

 

2.   to express possibility or impossibility (with comparative adjectives):

°The situation couldn’t be worse.

 

3.   to make suggestions:

°We could go to that new restaurant opposite to the cinema.

 

4.    to express willingness (boa vontade, disposição, voluntaiedade):

° I couldn’t possibly leave Tim here on his own.

 

 

 

COULD °  MANAGED TO °  WAS ABLE TO

° I managed to get/was able to get two tickets for the Cup Final yesterday. (=manged to/ was able to for a particular event in the past; never ‘to’  after could)

° Andrew could sing like an angel before his voice broke.

(could for general ability in the past; was able to is also possible but less usual)

 

 

MIGHT ° COULD

° As we came in to land, we could see the lights on the runway.

(could for ability with verbs of perception)

°We’d better wait. She might/could arrive at any moment.

(could or might for degrees of possibility; might expresses less certainty)

°Could I/ Might I use your phone?

(could or might for permission; might is more polite, but less common)

 

 

 

Conditional sense:

I could buy a new car if I had enough money

 

Para indicar que algo poderia ter sido feito, mas não foi:

Could have + past participle

 He could’ve tuned in, tuned in, but he tuned out.

 I could have lied, but I didn’t.

                       

MAY is used:

1.   to ask for permission in a formal way:

°May I open the door?

 

2.   to express possibility or uncertainty in a formal way:

°The peace conference  may find a solution to the problem.

 

3.   to express although clauses:

°She may be the boss, but that is no excuse for shouting like that.

4. to express wishes:

°“May the force be with you, Luke!”

 

5. Probability:

 (MAY have + past participle; MIGHT have + past participle)

   °Susan was very late. She may have missed her bus.

   °We all thought they might have survived the earthquake.

 

MIGHT is used:

1.   to express possibility or uncertainty in a informal way:

 

The peace conference might find a solution to the problem.

 

HIGH CERTAINTY	LOW POSSIBILITY
That may be Sidney.   That could / might be Sidney.	That might not be Sidney. That may NOT be Sidney. That can’t / couldn’t be Sidney.
LOW CERTAINTY	IMPOSSIBILITY