Four sentences about a missed train
Somebody did not arrive. Four sentences about it. Only two of them are deductions.
Four questions. Say what each sentence is doing.
1. He must have missed the train.
2. He should have caught the earlier one.
3. He can’t have missed it — I watched him get on.
4. He would have called if there were a problem.
The flat, after eleven days away
What was different
I came back on the Sunday night. The heating was off, which I had left on low, and the flat was cold enough that it must have been off for days rather than hours.
There was a plate in the rack, washed. I do not leave washing up. Somebody must have eaten here — and they can’t have been in a hurry, because they washed the plate and put it away in the wrong place, which takes longer than leaving it.
The post had been picked up off the mat and squared into a pile on the table. My mother has a key. It might have been her, although she would have texted. It could equally have been the landlord, who has a key he is not supposed to use.
The plant on the windowsill had been watered. That is the detail I keep going back to. Whoever came in, they cannot have been here for anything urgent — nobody waters a plant on their way to an emergency — and they can’t have expected me back before Sunday, or they would not have bothered.
Six pieces of evidence from the account. Match each to the claim it actually supports.
The past scale, and the sound of it
Deduction about the past
| Form | Claim | Example |
|---|---|---|
| must have + participle | The only explanation left, about something already over | Somebody must have eaten here. |
| must have been + -ing | The only explanation, about something in progress then | He must have been waiting outside. |
| might / could / may have + participle | One live possibility about the past | It might have been the landlord. |
| might not / may not have + participle | Possibly it did not happen | She might not have seen the message. |
| can’t / couldn’t have + participle | Eliminated — it did not happen | They can’t have been in a hurry. |
Same shape, different job
| Form | What it is doing | Test |
|---|---|---|
| must have gone | Deduction. I conclude that he went | Can you answer "what rules out the alternatives?" |
| should have gone | Criticism or regret. He did not go, and that was wrong | Does it contain a judgement about the person? |
| would have gone | Unreal past. In some other version of events, he went | Is there an if, said or implied? |
| could have gone | Two jobs. Deduction: possibly he went. Unreal: he had the chance and did not take it | Only the surrounding sentences tell you which |
The sound is why this is hard to hear. In speech have is almost never have. It is /əv/, and it attaches to the modal: must’ve /ˈmʌstəv/, might’ve /ˈmaɪtəv/, could’ve /ˈkʊdəv/, can’t’ve /ˈkɑːntəv/.
Two consequences. First, native speakers themselves write must of, because that is what it sounds like — you will see it, and it is still wrong. Second, learners who cannot hear the /əv/ produce he must been waiting, dropping the very word that puts the sentence in the past.
Say all five contracted forms twice before you go on. You cannot produce what you have not said.
Five questions.
1. The plate was washed and put away wrongly. Which?
2. You should have told me. What is this?
3. The light was on all night. Which is the deduction?
4. He could have taken the job. Without more context, what do you know?
5. How is must have pronounced in ordinary speech?
Reconstructing what happened
Two to four words per gap. Every gap is a modal plus have plus a participle.
The heating was off, so it off since at least Thursday. Somebody here, because the plate was washed. It my mother, but she me if it had been. They in a hurry, because they watered the plant, and they me back before Sunday, or they would not have bothered.
Seven sentences. One error each — three are form, four are the wrong job or the wrong strength.
1. He must been waiting outside.
2. She must of left before six.
3. They mustn’t have seen the sign.
4. You must have told me — I would have remembered. — the speaker means the opposite
5. He should have missed the train, because he isn’t here. — a conclusion, not a criticism
6. It must have been the landlord or my mother. — two live possibilities
7. She can’t have not received it.
Eleven days
Task card · Speaking · Pairs · 10 minutes
Between you, reconstruct what happened in that flat. Produce a single account you both accept.
Five minutes building it, five minutes defending it against the other pair beside you.
- Every claim carries a modal: must have, can’t have, might have.
- Every claim names its evidence in the same breath: they can’t have been in a hurry, because…
- Find the one detail your account does not explain. Say it out loud rather than hiding it.
- Then take the other pair’s account and try to break one must have. One only.
Something to notice while you argue. The moment a claim is challenged, most speakers reach for should have — well, they should have left a note. That is a real move, and it is a change of subject: it stops reasoning about what happened and starts judging somebody. Catch it when your partner does it, and when you do.
What broke, and how
Two questions.
1. When the other pair broke one of your must have claims, what had gone wrong?
2. Did anybody switch to should have under pressure?
Backwards, with the same test
Two questions. Twenty seconds.
1. What is the negative of must have gone?
2. Why do learners produce he must been waiting?
Next. A whole mystery, in groups, with every claim graded and every must open to challenge.