practical grammar I summer term MODALS I
CAN, past COULD / COULD
permission (be allowed to)
in the present/future
- in the first person it is more usual than „may”;
- in the second person both with the meaning of the speaker giving permission and the general idea of permission: You can park here = I allow it or You have a right to park here .
`could' when there is an idea of condition: Why don't you ring him? You could/can use my phone.
in the third person in informal English: He can take the car.
in the past
- in indirect speech: He said I could use his phone.
- general, open permission: On Sundays we could stay up late.
- in particular cases only with negation: We couldn't bring our dog into the restaurant.
Otherwise, i.e. in particular cases `be allowed to': I had a visa so I was allowed to cross the frontier.
Wherever `can' has no suitable morphological form, `be allowed to' takes over.
request for permission:
`could I?' (nr 1) for both formal and informal requests
`can I?' for informal requests
`can't I?' and `couldn't I?' are used to show that the speaker hopes for an affirmative answer
(`may' and `might' are not used this way)
questions about permission are expressed by `can' or `be allowed to', not `may'
possibility (`be possible to')
general possibility : You can't swim in this pool. It's too shallow.
occasional possibility; only in the present and past tense, and chiefly in the affirmative. Teenagers can be quite thoughtless.
That dog could be very dangerous.
3. ability (`be able to')
present/future :
`can' is more usual
with no existing morphological form of `can' (future, perfect), `be able to' takes over
`could' when there's an idea of condition: I could get you a copy. (if you want one)
`could' to introduce a request, as a more polite alternative to `would you?'Could you do it now?
past:
`could' and `was able to' for ability only: When I was a teenager I could/was able to swim faster.
`was able to' for ability + particular action: Thomas was left alone at last so he was able to read the chapter to the end.
BUT
`could' is possible in the negative when the action didn't take place: I had to haul an inflated mattress so I wasn't able to / couldn't swim fast.
and with the verbs of the senses: I could / was able to see him in the open door.
`could' + perfect infinitive is used
when the action was not performed or we don't know whether it was performed or not: She was able to make up the bed as opposed to: She could have made the bed.
when the speaker wants to express irritation at or reproach for the non-performance of the action: You `could/ `might have told her.
MAY, past MIGHT
permission (be allowed to)
present/future
in the first person (`I have the permission to...') less usual than `can' and `be allowed to'
in the second person (I give you permission to...) functions as the main form;
in the third person (`I give him permission to' - in formal English, otherwise `can' or `he has the right to' - chiefly used in impersonal statements concerning authority and permission: If convicted, an accused person may appeal.; in informal English - `can')
in the past
replaced by `be allowed to'
in indirect speech `might'
wherever `may' has no suitable morphological form, `be allowed to' takes over.
request for permission:
`may I?' for both formal and informal requests, a bit more formal than `can I?'
`might I?' more diffident than `may I?' , more uncertainty about the answer.
probability - speculation (`be likely to') [in TM under `possibility']
in the present/future both `may' and `might'
`might' slightly increases the doubt
in speech doubt can be increased by stressing `may/might': Lee `may/might get the contract.
in the 1st and 2nd conditionals, as an alternative for `will/would, to express a lower level of probability
in the past ,
only `might' is used, either when introduced by a verb in the past: I felt that she might not be telling the truth.
or in indirect speech,: Jones told me that Sue might be pregnant.
with the perfect infinitive, for speculations about past actions: Jane may/might have arrived.
only `might' when the main verb is in the past tense: She said she might have married a wrong man or in `veiled' third conditional: What a pity Marge got sick. She might have won the race.
the interrogative is normally expressed by `do you think?' or `be likely to': Do you think Mary Ann Spencer will marry a Smith? / Is Mary Ann Spencer likely to marry a Smith?
`may/might be + (infinitive) (continuous infinitive) (passive infinitive) (perfect infinitive, also with every other verb) can be replaced by `could' in the:
- affirmative: That glutton of a dog may/might/could be in the kitchen again.
Poor Mary, she may/might/could still be writing her essay. The light is on. That new law may/might could/be issued no earlier than next month. We must wait.
Jim may/might/could have sold his car. I see him walk to his office every morning.
interrogative: only `could' or `might': Might/could he be telling the truth?
negative: there is a difference between `could not' and `may/might not':
`may/might not' expresses a low level of probability: He may/might not have written it himself. (Perhaps he didn't write it himself.)
`could not' expresses a negative deduction: He couldn't have written it himself. (It's impossible that he wrote it himself.)