Level: intermediate
We can use a modal verb with have and a past participle:
| Subject | Modal | have | Past participle | |
|---|---|---|---|---|
| They | will | have | arrived | by now. |
| You | might | have | seen | the film. |
| Jack and Jill | would | have | been | late. |
We use a modal verb with have:
- to refer back from the present:
It's nearly eight o'clock. They will have arrived by now.
- to refer back from a point of time in the past:
We were very worried. We thought someone might have taken the car.
- to refer back from a point of time in the future:
We won't eat until they arrive. They might not have had supper.
- to refer to past time:
You should have helped her when she asked.
They might have got lost. Nobody knows where they are.
- Modal verbs with have 1
- Modal verbs with have 2
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Hello Mussorie,
As with all modal verbs, context is key to the meaning.
In general, would suggests an imagined choice, option or likely result; could describes possibility. For example:
I would go to the party - my choice or decision, if I were in a position to choose.
I could go to the party - it is possible for me to go.
Since like is a personal preference, it is logical that we use would like to (option/choice) rather than could like to (possibility).
In your sentences, would describes the likely or certain result, while could describes a possible but not certain result. You would miss the meeting is sure, if the condition is fulfilled. You could miss the meeting is not certain, even if the condition is fulfilled; it may depend on other factors.
Peter
The LearnEnglish Team
Hi Nuro,
Yes, we could use a passive here too: several brances of the bank have recently been opened up ... The meaning is the same, but the passive highlights the role of people more in this activity (opening up branches).
For open and some other verbs, we can put the thing as the subject (even though, logically speaking, you might think that a thing like a branch of a bank cannot act by itself). These verbs are called ergative verbs and you can find more explanations and examples here. I hope it helps :)
Best wishes,
Jonathan
The LearnEnglish Team
Hello Ahmed Imam,
All three are correct (well done!) and in general they all mean the same thing.
All the best,
Kirk
The LearnEnglish Team
Hello Ahmed Imam,
Typically grammars say that 'must' is used for internal obligations and 'have to' is used for external ones. This is a good guideline, but I'm not sure it always holds up, and in any case it's sometimes difficult to distinguish between external and internal. For example, to my mind, all of the sentences you wrote could express internal motivation. On the other hand, I'd probably not use the first one to express external obligation -- but then again, I almost never use the modal verb 'must', so it may have more to do with that than anything else.
I hope this helps. By the way, if there's a specific point you want to ask about, please mention it in your comment. We could often write much more in our explanations, but simply don't have the time to write comprehensive replies. We're happy to try to help with specific queries, but can't afford to make guesses.
All the best,
Kirk
The LearnEnglish Team
Hi Nuro,
Both forms are possible here. I don't believe this is a question from our site so you'd have to ask the author why the key allows only 'must'.
Peter
The LearnEnglish Team
Hello AsahiYo20,
You could use 'might have', but it would express probability (a guess) instead of possibility. As you note, 'could have' expresses that you had the possibility of borrowing it, but 'might have' would express the idea perhaps you would have borrowed it (if, for example, the circumstances had been different).
'may have' means the same thing as 'might have' here. 'could have' can also be used to make guesses about the past, and thus could also be used here, but most of the time we use 'might have' or 'may have' to do this.
Yes, 'could not have' would express impossibility here. 'may not' would mean the same as 'might have'.
All the best,
Kirk
The LearnEnglish Team
Hi Sunyoung1005,
We have a page devoted to the difference between can and could. You can find it here:
https://learnenglish.britishcouncil.org/english-grammar-reference/can-and-could
I think if you take a look at that page you can try to answer your own question. We'll be happy to confirm or to correct, of course!
Peter
The LearnEnglish Team
Hi AkiraTa05,
Good questions. I'll try to answer below.
Q1: yes! Both can't have and couldn't have are the opposite of must have, for the meaning of deduction.
Q2: yes. You could replace could with might in those sentences.
You might like to have a look at this page, for more examples: https://learnenglish.britishcouncil.org/grammar/intermediate-to-upper-intermediate/modals-deductions-about-the-past
Best wishes,
Jonathan
The LearnEnglish Team
Hello Sunyoung1005,
Will have is an expression of belief. Must have is similar, but it is generally used when we have evidence of some kind (including past experience) which causes us to form an expectation. Must have carries a sense that the speaker would be surprised if things were not as he or she expects.
I think you could use will have in the first sentence, though must have is better as it carries the sense of I would be amazed if not.
Must have does not work in the second sentence as the context suggests that the writer sent the form. You could use must have if there were a time reference so the speaker could express an expectation that the time has been sufficient.
Must have is possible in the third sentence for the reasons above.
Peter
The LearnEnglish Team
Hello Sunyoung1005,
Yes, that's right.
With the second sentence, must is possible because the evidence could be a knowledge of how the postal service works, but will is also fine.
Peter
The LearnEnglish Team
Hello ysl_cherry,
I believe this was a temporary problem and should now be fixed. I have checked on my computer and am able to access the site without logging in.
Peter
The LearnEnglish Team
Hello Rsb,
It is possible to use perfect modal verbs with future reference when we are looking back from a point further in the future. The future perfect (will have + verb3) is an example of this:
May/might can replace will to make the prediction less certain:
We can also use the perfect modal (may/might have + verb3) to express a counter-factual with an if-clause (or implied if-clause).
For example, imagine we are talking on Wednesday. I plan to meet my friend on Thursday. However, there is an earthquake and all travel is cancelled. In that situation I might say this:
(would, could and may are all also possible here)
As you can see, context is crucial.
Peter
The LearnEnglish Team
Hello pipilica,
All of the sentence are possible, but they have different meanings and implied if-clauses.
1. This is fine as it stands. It functions as a criticism of John's performance, which did not reach expectations. It suggests the speaker does not understand why John did not play well.
2. This sentence describes an alternative outcome which was possible but not certain. It implies an if-clause:
3. This sentence is similar to the second, but is more certain of its conclusion. It does not (like #2) tell us that an alternative was possible, but that the alternative was certain if the condition were met
Peter
The LearnEnglish Team
Hello Ahmed Imam
Both of those are correct and sound natural -- good work. The first sentence speaks about the past and the second one about the present.
All the best
Kirk
The LearnEnglish Team
Hello alist123
We sometimes use the relative pronoun 'when' with words that express time (for example, 'day', 'week', 'hour', 'time', etc.), but often we do not. I would recommend 'time we spent' instead of 'time when we spent'.
You can read a little more about this in the last section on our Relative pronouns and relative clauses page.
All the best
Kirk
The LearnEnglish Team
Hello Aniyanmon
These replies don't sound correct to me. Perhaps there is some context in which it would make sense to reply with 'would have' here, but I can't think of one off the top of my head.
All the best
Kirk
The LearnEnglish Team
Hello Aniyanmon
Yes, both of those sentences are grammatically correct.
All the best
Kirk
The LearnEnglish Team
Hello Aniyanmon
As is explained just before the first exercise above, a modal verb plus 'have' can be used to refer back from a time in the future. In the question and answer you cite from the book, that future time is 'by next year' (or 'by that time'). So it is correct here.
Note that in this case, 'should' is not giving advice -- it is used to talk about probability (see the Certainty section on that page for more examples).
Thanks for asking this question on a more appropriate page.
All the best
Kirk
The LearnEnglish Team
Hello Samavor,
No, you cannot use should have with that meaning. As a concept, should describes something desirable or advisable, not something contingent on a counter-factual past. You could use a phrase like ...it would have been a good idea to... or ...it would have been sensible to...
Peter
The LearnEnglish Team
Hi hadi.khorand,
'can have' + past participle is not used in affirmative verb phrases (e.g. 'She
can have gonehome') -- instead we use 'could have' + past participle (e.g. 'She could have gone home'). The latter refers to a past possibility.'can have' + past participle can be used in negative verb phrases (e.g. 'She can't have gone home -- her car keys are still here.'), where it expresses certainty about the past, and it can also be used in interrogative verb phrases (though it is a bit unusual): 'Where can she have gone?'
All the best,
Kirk
The LearnEnglish Team
All the best,
Kirk
The LearnEnglish Team
Hi Goktug123,
Your first interpretation of the first sentence is correct -- the speaker supposes that the car was John's. The second sentence is similar to the first -- the speaker makes a supposition about a past event.
As you suggest, 'would have' + v3 is also commonly used in third conditional structures, which can be used, for example, to speak about regrets. For example, 'If I hadn't taken that job, I would have finished my studies.'
All the best,
Kirk
The LearnEnglish Team