Modal auxiliary verbs + ‘have’
Introduction
We should have turned left, not right - now we're lost.
Definition
This is a structure which is used with modal auxiliary verbs and with verbs which have a similar function to talk about the past, present or future. For more information on these, see Introduction to modal verbs and the following:
| Can
| Could
| Should
| Ought to
| Might and may
| Will
|
| Shall
| Would
| Must
| Have to
| To need / need
|
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Construction
Affirmative: subject + modal + 'have' + past participle
I should have gone.
Negative: subject + modal + 'not' + 'have' + past participle
I shouldn't have gone.
Interrogative: modal + subject + 'have' + past participle
Should I have gone?
Note that this construction is not possible for all the verbs listed above or all the uses below. In particular:
1. In the affirmative, can have and need have are only used with restricting words - see below.
2. may not have is not contracted.
3. may have is not used in the interrogative.
4. must have is only used in the affirmative.
5. ought to have, have to have and to need to have are constructed as follows:
|
| Ought to have | Have to have | To need to have |
| Affirmative |
subject + 'ought to' + 'have' + past participle
I ought to have done it.
|
subject + 'have to' + 'have' + past participle
He has to have done it. |
subject + 'need to' + 'have' + past participle
He needs to have done it. |
| Negative |
subject + 'ought not to' + 'have' + past participle
I oughtn't to have done it.
|
|
subject + 'do not' +'need to' + 'have' + past participle
He doesn't need to have done it.
|
| Interrogative |
'ought' + subject + 'to have' + past participle
Ought I to have done it?
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|
'do' + subject 'need to' +'have' + past participle
Does he need to have done it?
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Uses
This structure can be used in some of the same ways as standard modal auxiliary verbs in past, present and future contexts.
The main uses are listed below.
| Modal | Use | Examples |
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Can have
|
Possibility [interrogative only]
Deduction [rare in the affirmative form - only with words such as 'only', 'hardly' and 'never'.]
|
How can you have forgotten again? I reminded you this morning!
I can only have been at the meeting for an hour but it felt like three - it was so boring.
You can't have been cold - it was 30˚ and you were wearing a coat.
It can't have been easy with four young children and a full-time job - how did you manage?
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|
Could have |
Possibility in the past, present or future
The possibility of things that didn't happen
Speculation about the past
Unrealistic situations
With 'I wish'
As 'would be able to' in conditional sentences
Reproach |
"Where was Lionel this morning - I couldn't find him?" "I'm not sure. He could have been in a meeting room."
I could have gone to the US to work but I took a job in London instead.
Thanks for your help last week - I couldn't have done it without you.
He could have been a doctor now but he left university to travel round the world.
I couldn't have worked today (if you'd asked me); I have an important appointment.
"What shall we do tomorrow?" "Well, we could have gone cycling with everyone else - the weather forecast is great. But I still haven't fixed my bike so let's go for a walk instead." [It would have been possible if I'd fixed my bike.]
You could have started a fire when you left that cigarette there - you really should be more careful.
"Why isn't Antoinette here yet?" "I don't know but she could have decided to go to lunch with the client she was visiting this morning."
We had a great time in Italy; I could have stayed there forever.
I couldn't have worked for your last boss - he was far too demanding.
I wish we could have had a meeting last week; the problem is just getting worse.
If you'd asked me, I could have helped you.
You could have reminded me about the meeting! I was 10 minutes late.
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|
Should have |
Advice in retrospect
The best or right thing to have done in the past - maybe some regret
Expectation
Deduction
Regret in the present
Opinion - more tentative than 'think' |
You should have gone by train.
You shouldn't have married him.
We should have discussed this with the client before making a decision.
Should I have ordered some more of these?
I shouldn't have shouted at you earlier - I'm really sorry.
She worked hard and she should have passed her exam - I don't know why she didn't.
It should have been delivered yesterday - I'm not happy with their service.
He should have finished lunch by now - I'll try calling him again.
Don't worry. It's not too late to change the order - they shouldn't have dispatched it yet.
I should have been at home now but I'm still stuck at work.
"Do you think the food here will be OK?" "Mmm, I should have thought so. Let's try it."
I shouldn't have thought it would rain today.
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Ought to have [rare in negative and interrogative]
|
Advice in retrospect [less common than should have]
The best or right thing to do
Expectation |
You ought to have gone by train.
He ought to have worn a helmet.
They ought to have arrived by now.
|
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Might/may have |
Possibility in the past [may have is not possible in the interrogative]
Reproach
To highlight a contrast between positive and negative |
The report may have been on the printer - I forgot to look there.
Susan wasn't in her office but she might have been in the canteen.
You might have helped me but you just stood there watching!
She might/may not have been punctual but she was very efficient. [=Although she wasn't punctual, she was very efficient.]
She might/may have been punctual but she wasn't very efficient.
|
|
Will have |
Deduction
Future actions and states
|
"Who was Chantal talking to on the phone?" "It'll have been her boyfriend. He calls her every afternoon."
She'll have finished by now.
See future perfect.
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Shall have |
Future actions and states
|
See future perfect.
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|
Would have |
Opinion
Conditionals
Wishing
Hypothetical situations
Deduction in the past, especially when based on historical evidence
|
I wouldn't have thought you'd like Japanese food - that surprises me.
I'd have helped you if you'd asked.
I wouldn't have been as successful now if I hadn't worked so hard.
I'd have loved to live in the countryside when I was young but I grew up in the city.
The traffic was terrible this morning - it would have been quicker to walk.
In the last century, more people would have lived in this region than now.
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|
Must have |
Deduction |
"Who was Chantal talking to on the phone?" "It must have been her boyfriend. He calls her every afternoon."
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|
Have to have |
Necessity [see future perfect and note below]
Deduction |
We have to have finished this by tomorrow.
"Who was Chantal talking to on the phone?" "It has to have been her boyfriend. He calls her every afternoon."
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To need
|
Necessity [see future perfect and note below]
|
I need to have finished this by tomorrow.
To reach our targets, we don't need to have sold as many cars by the end of this month as last month.
Do we need to have sent the invitations by Thursday or Friday?
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Need |
Necessity [rare in the affirmative - only with words such as 'only', 'hardly' and 'never'.]
|
I need only have stayed for an extra ten minutes but I decided not to.
They needn't have spent so much money - what a waste!
Need we have booked the biggest meeting room? We're only expecting three people.
|
‘Could have’ or ‘may/might have’
These are both used to talk about possibility but in different ways.
| They could have played golf yesterday. | = all the right conditions existed but they didn't play.
|
| They might/might not have played golf yesterday.
| = we don't know if they played or not. |
| They couldn't have played golf yesterday. | = something prevented them and they didn't play. |
Present continuous
Some of these can be followed by the present continuous for some uses. For example:
1. Possibility
He could have been having lunch.
He couldn't have been having lunch.
I could have been relaxing at home now but I'm still at work.
He might/may have been having lunch.
2. Deduction
He can't have been having lunch - the canteen was closed.
He should have been having lunch.
He must have been having lunch.
He'll have been having lunch.
He has to have been having lunch.
3. Reproach
You could have been helping me instead of watching TV.
4. Regret
I should have been relaxing at home now but I'm still at work.
5. Advice
You should have been learning Japanese, not English.
You ought to have been learning Japanese, not English.
6. The best or right thing
We should have been spending less money on new computers.
We ought to have been spending less money on new computers.
7. Expectation
They should have been working on the installation yesterday.
They ought to have been working on the installation yesterday.
8. Deduction
"I called Kerry but she didn't answer."
"She'd have been having lunch, I expect."
'To need' and 'need'
Note the following different meanings:
I needn't have bought so much cheese. [I bought some but when I got home, I discovered I already had a lot in the fridge - I didn't know it was there.]
I went shopping but I didn't need to buy chocolate because I already had some. [I didn't buy any because I knew I had some.]
The future perfect
Note that this structure has the same construction as the future perfect simple.
We'll have finished this by Friday.
As well as 'will' and 'shall', we can use some modal verbs for this tense.
We might have finished this by Friday. [possibility]
We should have finished this by Friday. [expectation]
We ought to have finished this by Friday. [expectation]
We need to have finished this by Friday. [necessity]
We have to have finished this by Friday. [necessity/obligation]
Examples
He can never have had dance lessons!
"I've postponed next week's meeting because I haven't had time to prepare for it." "Well, we couldn't have had it next week anyway because too many of us will be on holiday." "Oh yes, I forgot about that."
My train ought to have been here by now but there was a delay, so I'll be late - sorry. I should have driven instead.
I miss working at the bank. It might not have been the most exciting job but I had great colleagues.
I'm sorry Akira isn't here yet - he'll have been held up in the rush hour traffic.
"It's not bad but I'd have done this part differently." "OK, I'll change it."
It must have been raining.
"What do you think? Remember we have to have decided this before we meet them again."
He needn't have worried - of course she said yes.
Some common expressions
| Expression | Meaning | Example |
|
'may well have' + past participle
|
Someone probably did something but doesn't remember. |
"You said you wouldn't be here tonight." "I may well have said that but here I am anyway!"
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'could have' + 'sworn' |
To have been sure about something. |
I can't find my keys. I could've sworn I left them on my desk but they're not there.
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'You should have' + past participle |
'I wish you had...' There's a suggestion that someone has missed something good. |
You should have seen her reaction when I told her the news!
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'Who'd have thought it?' |
Expresses great surprise. |
"Tom asked Liz to marry him." "I know - who'd have thought it!"
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'It could have been worse.' |
'We shouldn't worry - it wasn't too bad.' |
"There was a train strike last week and half the team couldn't get to work." "Oh well, it could have been worse - this isn't our busiest month."
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'might have known' |
Expresses a lack of surprise. |
"Who ate the last cake?" "It was Lucie." "Ah...I might have known it!"
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