COULD HAVE
Remember:
COULD is a modal verb (called « modal »).
Modals are used before ordinary verbs.
COULD is used for Ability, Past form of CAN, with senses verbs, action not realistic, polite request, « COULD » can be used to talk about the past, the present or the future.
COULD HAVE: here, « have » is the base form (infinitive without « to »).
We use « could have » when we want to show:
– that something is possible NOW:
It’s seven o’clock. They could have arrived now.
– that something was possible IN THE PAST:
It’s seven o’clock. They could have arrived hours ago.
Remember:
COULD is used to talk about ability of somebody.
COULD HAVE is used to talk about something
that somebody was capable to do, but he didn’t do it. (Possible in the PAST)
I could have done it (but I didn’t want to).
He could have worked as an accountant, but he didn’t want to. He’s a singer.
I could have worked in New York, but I didn’t want to. I work in London.
And because the person didn’t do it,
we use the form « could have » to make a critical remark.
You could have helped me instead of just looking at me.
They could have done it themselves.
You could have phoned me to tell me about your delay.
I could have done it before, but I was tired. Excuse me.
COULD NOT HAVE is the negative form. (couldn’t have)
We talk about something that somebody was NOT capable to do.
(Impossibility in the PAST).
I couldn’t have got the job. I don’t speak italian!
I couldn’t have done it alone. Thank you for your help.
We couldn’t have found their house without the GPS.
COULD HAVE:
When we don’t know what has happened, we imagine it.
a/ with « could have »:
He could have phoned her. (maybe he did, but we don’t know).
He could have came earlier. (maybe he did, but we don’t know).
She could have gone to the airport earlier.
b/ with « may/might have » too.
He may/might have phoned her. (maybe he did, but we don’t know).
He may/might have came earlier. (maybe he did, but we don’t know).
She may/might have gone to the airport earlier.
c/ with « can have » too, but only interogative & negative form.
Interrogative form: Can it have happened? (question?)
Can he have phoned her? (maybe he did, but we don’t know).
Can he have came earlier. (maybe he did, but we don’t know).
Can she have gone to the airport earlier. (maybe she did, but we don’t know).
Can you have done it?
Can you have broken the car?
Can she have called me?
Note: « have » is the infinitive without « to » in this case!
Negative form: It can’t have happened! (negative!)
He can’t have phoned her! (maybe he can’t, we don’t know).
He can’t have came earlier. (maybe he can’t, we don’t know).
She can’t have gone to the airport earlier. (maybe she can’t, we don’t know).
He can’t have done it so quickly, that’s impossible!
They can’t have heard us.
Remember:
When we don’t know what has happened, we imagine it with:
« could have », may have », might have » (maybe he have done it, but we don’t know).
« can + subject + have » and « can’t have » (only in interrogative and negative form).
COULD HAVE:
When we know that something didn’t happen, and we imagine that it could!
You could have lost your keys! Be careful.
You could have broken the car. Drive better!
I could have passed my exam if I’d studied.
I could have gone to university, if I’d passed my exams.
He could have finished the marathon, if he’d trained harder.
COULD HAVE BEEN:
We talk about something that HAVE NOT happen in the present.
(Possible in the PRESENT).
« been » is the perfect tense of the verb « to be » (was,were/been).
I could be the leader. (possible in the present)
=> I could have been the leader. (possible in the PRESENT, but have not happened!).
I could have been working in London (now) but I didn’t get the job.
He could have been studying in NY (now) but his registration to university wasn’t accepted
He could have been a basketball player (now) but he was not enough taller.
He could have been a basketball player, if he had been a little taller.
He could have been a basketball player, if he were just a little taller.
CAN COULD and TO BE ABLE TO: