(redirected from could have)


aux.v.Past tense of can1
1. Used to indicate ability or permission in the past: I could run faster then. Only men could go to the club in those days.
2. Used with hypothetical or conditional force: If we could help, we would.
3. Used to indicate tentativeness or politeness: I could be wrong. Could you come over here?
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


1. used as an auxiliary to make the past tense of can1
2. used as an auxiliary, esp in polite requests or in conditional sentences, to make the subjunctive mood of can1: could I see you tonight?; she'd telephone if she could.
3. used as an auxiliary to indicate suggestion of a course of action: you could take the car tomorrow if it's raining.
4. (often foll by well) used as an auxiliary to indicate a possibility: he could well be a spy.
[Old English cūthe; influenced by would, should; see can1]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(kʊd; unstressed kəd)

1. a pt. of can 1.
auxiliary verb.
2. (used to express possibility): That could never be true.
3. (used to express conditional possibility or ability): You could do it if you tried.
4. (used in making polite requests): Could you open the door for me, please?
5. (used in asking for permission): Could I borrow your pen?
6. (used in offering suggestions or advice): You could ask for more information.
[Middle English coude, Old English cūthe; modern -l- (from would1, should) first attested 1520–30]
usage: See care.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.


couldbe able to

These words are used to talk about ability, awareness, and possibility. They are also used to say that someone has permission to do something. These uses are dealt with separately in this entry. Can and could are called modals.

Both can and could are followed by an infinitive without to.

I envy people who can sing.
I could work for twelve hours a day.
1. negative forms

The negative form of can is cannot or can't. Cannot is never written 'can not'. The negative form of could is could not or couldn't. To form the negative of be able to, you either put not or another negative word in front of able, or you use the expression be unable to.

Many elderly people cannot afford telephones.
I can't swim very well.
It was so dark you could not see anything.
They couldn't sleep.
We were not able to give any answers.
We were unable to afford the entrance fee.
2. ability: the present

Can, could, and be able to are all used to talk about a person's ability to do something. You use can or be able to to talk about ability in the present. Be able to is more formal than can.

You can all read and write.
The animals are able to move around, and they can all lie down.
Lisa nodded, unable to speak.

Could is also used to talk about ability in the present, but it has a special meaning. If you say that someone could do something, you mean that they have the ability to do it, but they don't in fact do it.

We could do much more in this country to educate people.
3. ability: the past

You use could or a past form of be able to to talk about ability in the past.

He could run faster than anyone else.
A lot of them couldn't read or write.
I wasn't able to answer their questions.

If you say that someone was able to do something, you usually mean that they had the ability to do it and they did it. Could does not have this meaning.

After two weeks in bed, he was able to return to work.
The farmers were able to pay their employees' wages.

If you want to say that someone had the ability to do something but did not in fact do it, you say that they could have done it.

You could have given it all to me.
You could have been a little bit more careful.

If you want to say that someone did not do something because they did not have the ability to do it, you say that they could not have done it.

I couldn't have gone with you, because I was in London at the time.

If you want to say that someone had the ability to do something in the past, although they don't now have this ability, you say that they used to be able to do it.

I used to be able to sleep anywhere.
You used to be able to see the house from here.
4. ability: the future

You use a future form of be able to to talk about ability in the future.

I shall be able to answer that question tomorrow.
5. ability: reporting structures

Could is often used in reporting structures. For example, if a woman says 'I can speak Arabic', you usually report this as 'She said she could speak Arabic'.

She said I could bring it back later.
6. ability: 'be able to' after other verbs

Be able to is sometimes used after modals such as might or should, and after verbs such as want, hope, or expect.

I might be able to help you.
You may be able to get extra money.
You should be able to see that from here.
She would not be able to go out alone.
Do you really expect to be able to do that?

Don't use can or could after any other verbs.

7. 'being able to'

You can use an -ing form of be able to.

He liked being able to discuss politics with Veronica.

There is no -ing form of can or could.

8. awareness

Can and could are used with verbs such as see, hear, and smell to say that someone is or was aware of something through one of their senses.

I can smell gas.
I can't see her.
I could see a few stars in the sky.
9. possibility: the present and the future

Could and can are used to talk about possibility in the present or future.

You use could to say that there is a possibility that something is or will be true.

Don't eat it. It could be a toadstool.
He was jailed in February, and could be released next year.

Might and may can be used in a similar way.

It might be a trap.
Kathy's career may be ruined.

Be Careful!
Don't use 'could not' to say that there is a possibility that something is not true. Instead you use might not or may not.

It might not be possible.
It may not be easy.

If you want to say that it is impossible that something is true, you use cannot or could not.

You cannot possibly know what damage you caused.
It couldn't possibly be true.

You use can to say that something is sometimes possible.

Sudden changes can sometimes have a negative effect.
10. possibility: the past

You use could have to say that there is a possibility that something was true in the past.

He could have been in the house on his own.

Might have and may have can be used in a similar way.

She might have found the information online.
It may have been a dead bird.

You also use could have to say that there was a possibility of something being true in the past, although it was not in fact true.

It could have been worse.
He could have made a fortune as a lawyer.

Be Careful!
Don't use 'could not have' to say that there is a possibility that something was not true. Instead you use might not have or may not have.

She might not have known the password.

If you want to say that it is impossible that something was true, you use could not have.

The decision couldn't have been easy.
The man couldn't have seen us at all.
11. permission

Can and could are used to say that someone is allowed to do something.

You can take out money at any branch of your own bank.
He could come and use my computer.

Cannot and could not are used to say that someone is or was forbidden to do something.

You can't bring strangers in here.
Her dad said she couldn't go out during the week.
Collins COBUILD English Usage © HarperCollins Publishers 1992, 2004, 2011, 2012
mohlmohl by
할 수 있었다
būčiau galėjęsbūtum galėjęsgalėčiaugalėtum
ubrániť sazabrániť
…-ebil di…muktedir olmak
có thể


[ˈkʊd](STRONG) [kəd] pt of can
(past possibility)
In those days you could get a job easily → À l'époque, on pouvait facilement trouver du travail.
I couldn't sleep because of the noise → Je ne pouvais pas dormir à cause du bruit.
I couldn't eat it all → Je n'ai pas pu tout manger.
I could see that something was wrong → Je voyais bien que quelque chose n'allait pas.
I couldn't understand a word → Je ne comprenais rien.
(present possibility)
You could be right → Vous avez peut-être raison.
He could be in the library → Il est peut-être dans la bibliothèque.
They could have forgotten → Ils ont peut-être oublié.
She could have been delayed → Il se peut qu'elle ait été retardée.
(future possibility)
You could hire a bike → Tu pourrais louer un vélo.
You could hurt yourself → Tu pourrais te faire mal.
(in requests)
Could I speak to you in private? → Est-ce que je pourrais vous parler seul à seul?
He asked if he could make a phone call → Il a demandé s'il pouvait passer un coup de fil.
Collins English/French Electronic Resource. © HarperCollins Publishers 2005


(kud) negative short form couldn't (ˈkudnt) verb
1. past tense of can . They asked if I could drive a car; I said I couldn't; She asked if she could go.
2. used to express a possibility. I could go but I'm not going to; I could do it next week if you helped me.
could have
used to express a possibility in the past. We could have gone, but we didn't.
Kernerman English Multilingual Dictionary © 2006-2013 K Dictionaries Ltd.


يَسْتَطِيعُ mohl kunne könnte μπορούσα poder voida avoir pu moći potevo, potevi, ecc. ・・・できた 할 수 있었다 kunnen kunne móc conseguir, pretérito de can мочь kunde สามารถ muktedir olmak có thể
Multilingual Translator © HarperCollins Publishers 2009
References in classic literature ?
Having scoured the whole coast of the enemy, as well as any of Homer's heroes ever did, or as Don Quixote or any knight-errant in the world could have done, he returned to Molly, whom he found in a condition which must give both me and my reader pain, was it to be described here.
This discrepancy, of which, of course, Reed could have had no knowledge at the time, concurred with other circumstances, to occasion afterwards some mysterious speculations and dark surmises as to the real fate of Cass; but as no substantial grounds were ever adduced for them, we forbear to throw any deeper shades into this story of sufferings in the wilderness.
It was about two hours before night when, our guide being something before us, and not just in sight, out rushed three monstrous wolves, and after them a bear, from a hollow way adjoining to a thick wood; two of the wolves made at the guide, and had he been far before us, he would have been devoured before we could have helped him; one of them fastened upon his horse, and the other attacked the man with such violence, that he had not time, or presence of mind enough, to draw his pistol, but hallooed and cried out to us most lustily.
Miss Skiffins's composure while she did this was one of the most remarkable sights I have ever seen, and if I could have thought the act consistent with abstraction of mind, I should have deemed that Miss Skiffins performed it mechanically.
In one well-marked instance, I put the comb back into the hive, and allowed the bees to go on working for a short time, and again examined the cell, and I found that the rhombic plate had been completed, and had become perfectly flat: it was absolutely impossible, from the extreme thinness of the little rhombic plate, that they could have effected this by gnawing away the convex side; and I suspect that the bees in such cases stand in the opposed cells and push and bend the ductile and warm wax (which as I have tried is easily done) into its proper intermediate plane, and thus flatten it.
I was able practically to show this fact, by covering the edges of the hexagonal walls of a single cell, or the extreme margin of the circumferential rim of a growing comb, with an extremely thin layer of melted vermilion wax; and I invariably found that the colour was most delicately diffused by the bees--as delicately as a painter could have done with his brush--by atoms of the coloured wax having been taken from the spot on which it had been placed, and worked into the growing edges of the cells all round.
As natural selection acts only by the accumulation of slight modifications of structure or instinct, each profitable to the individual under its conditions of life, it may reasonably be asked, how a long and graduated succession of modified architectural instincts, all tending towards the present perfect plan of construction, could have profited the progenitors of the hive-bee?
Hence I can see no real difficulty in any character having become correlated with the sterile condition of certain members of insect-communities: the difficulty lies in understanding how such correlated modifications of structure could have been slowly accumulated by natural selection.
Therefore, the Romans, foreseeing troubles, dealt with them at once, and, even to avoid a war, would not let them come to a head, for they knew that war is not to be avoided, but is only to be put off to the advantage of others; moreover they wished to fight with Philip and Antiochus in Greece so as not to have to do it in Italy; they could have avoided both, but this they did not wish; nor did that ever please them which is for ever in the mouths of the wise ones of our time:--Let us enjoy the benefits of the time--but rather the benefits of their own valour and prudence, for time drives everything before it, and is able to bring with it good as well as evil, and evil as well as good.
Let any one now consider with that little difficulty the king could have maintained his position in Italy had he observed the rules above laid down, and kept all his friends secure and protected; for although they were numerous they were both weak and timid, some afraid of the Church, some of the Venetians, and thus they would always have been forced to stand in with him, and by their means he could easily have made himself secure against those who remained powerful.
And as if it were not enough to have aggrandized the Church, and deprived himself of friends, he, wishing to have the kingdom of Naples, divides it with the King of Spain, and where he was the prime arbiter in Italy he takes an associate, so that the ambitious of that country and the malcontents of his own should have somewhere to shelter; and whereas he could have left in the kingdom his own pensioner as king, he drove him out, to put one there who was able to drive him, Louis, out in turn.
Therefore, if France could have attacked Naples with her own forces she ought to have done so; if she could not, then she ought not to have divided it.
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