Use modal verbs + have + V3 to work out what probably, certainly or impossibly happened.
In Unit 6 you learned to make deductions about the present: She must be tired. Now you will do the same for the past. When you have no direct proof but you can read the clues, English lets you say how certain you are with a single, powerful structure: a modal verb + have + past participle (V3).
This is the language of detectives, scientists and confident speakers. Instead of "Maybe he forgot" you can say "He must have forgotten" (I'm sure), "He can't have forgotten" (that's impossible) or "He might have forgotten" (perhaps). One small change of modal, and your whole level of certainty changes with it.
The pattern never changes: pick your modal, then always add have and the past participle (V3). The modal shows how sure you are; the have + V3 shows that you are talking about the past.
| Function | Structure | Example |
|---|---|---|
| Certain — it happened | must + have + V3 | She must have left early. |
| Certain — it did NOT happen | can't / couldn't + have + V3 | He can't have known the truth. |
| Possible — perhaps | might / may / could + have + V3 | They might have missed the bus. |
| Continuous idea | modal + have been + V-ing | You must have been sleeping. |
Think of a line from 100% yes to 100% no. The modal you choose places your idea somewhere on that line. This is the whole point of deduction: not the fact, but how confident you are about it.
| Certainty | Modal | Example |
|---|---|---|
| ~100% — I'm sure it happened | must have | The road is wet; it must have rained. |
| ~50% — perhaps it happened | might / may / could have | She's late; she may have overslept. |
| ~0% — I'm sure it did NOT happen | can't / couldn't have | He can't have finished so quickly. |
These two are a pair: must have for what you are sure did happen, can't have for what you are sure did not. You read the same evidence, but it points in opposite directions.
could have + V3 does two useful jobs. First, like might/may have, it shows a past possibility. Second — and this is very B2 — it describes a missed opportunity or a near miss: something that was possible but did not actually happen.
| Meaning | Example | Idea |
|---|---|---|
| Past possibility (= might have) | She could have taken the earlier train. | Perhaps she did. |
| Missed opportunity | We could have won, but we played badly. | It was possible; it did not happen. |
| Near miss / lucky escape | You could have hurt yourself! | It nearly happened; luckily it did not. |
The only difference is when the situation is true. Add have to move a present deduction into the past. Compare each pair carefully — the certainty is the same, only the time changes.
| Idea | Present (Unit 6) | Past (Unit 7) |
|---|---|---|
| Certain | She must be tired. | She must have been tired. |
| Impossible | He can't be at home. | He can't have been at home. |
| Possible | They might be lost. | They might have been lost. |
These are the errors B2 students still make with past deduction. Check your own sentences against every row.
| Wrong ✗ | Right ✓ | Why? |
|---|---|---|
| She must have went home. | She must have gone home. | use the participle (V3 = gone), not the past (went). |
| He must left already. | He must have left already. | the structure needs have: must + have + V3. |
| They mustn't have seen us. | They can't have seen us. | for past impossibility use "can't have", not "mustn't have". |
| You can't have been knowing that. | You can't have known that. | "know" is stative → no continuous form. |
| It must have rain last night. | It must have rained last night. | after "have" you need the participle (rained). |
Two friends wonder why Dan never came to their group study session. Read it twice and watch the certainty shift: must have for a sure conclusion, can't have for an impossible one, and might/could have for a guess.
Choose the correct answer. — 10 questions, each one is marked instantly. Questions get harder as you go.
Learn the words, then use them to explain what probably happened.
Write 8 sentences explaining a real or imagined mystery — something odd that happened and how you worked out the reason. Use at least 8 of the words above.
Sentence starters (you can begin with these):
Değerlendirme öğretmenin tarafından yapılacak. (Your teacher will review your task.)
Read the mystery, then answer the questions.
Good readers prepare before they start. Before you read, think about these three questions (you do not need to write the answers):
Words to spot (from the Speaking section): clue · evidence · suspect · witness · trace · vanish · deduce · suspicious
When Inspector Hale arrived at the old house, the study door was still locked from the inside, yet the famous diamond necklace had vanished from the safe. The owner, Mr Vance, insisted that nobody could have entered the room. Nevertheless, Hale was certain that someone must have taken it, because jewels do not simply disappear on their own.
The theft had happened during a busy family weekend. Mr Vance had invited his sister, her three teenage children and two of their classmates, so the old house had been crowded and noisy until well past midnight. Because so many young people had been drifting between the games room, the kitchen and the garden, Hale realised that almost anyone could have slipped upstairs without being noticed. Nevertheless, most of the teenagers had spent the evening filming a dance video for social media in the front hall, and the time stamps on their phones proved it. They can't have been anywhere near the study when the necklace vanished; therefore, the inspector crossed them off his list one by one.
Hale examined the scene carefully. The window was wide open, although it was a freezing winter night. Therefore, he reasoned, the thief must have climbed in from the garden. However, there were no ladders and no footprints in the flowerbed below. The criminal couldn't have jumped that high, and he can't have flown, so how had he reached the second floor?
Back inside the study, the inspector studied the heavy old safe. It had not been forced or scratched, so whoever had opened it must have known the four-digit code. Only someone close to the family could have learnt those numbers, which meant a passing stranger can't have been responsible. A younger cousin named Leo had boasted at dinner that he could crack any lock in the world; yet his story fell apart at once, since he had spent the entire evening losing noisily at video games in front of six laughing witnesses. He might have wanted the diamonds, Hale admitted, but he certainly couldn't have taken them. Another cousin insisted the family cat must have knocked the necklace somewhere, although even a clever cat can't open a locked safe.
That evening, the teenagers had actually turned the mystery into a noisy debate of their own. One of them argued that a professional burglar must have broken in from the roof, whereas another insisted the necklace could simply have been mislaid. A third pointed out that no window downstairs was broken, so an outsider can't have got in at all. Hale listened quietly from the doorway. Their guesses were wild, yet one comment stayed with him: 'Whoever did it must have been able to climb,' a girl said, 'because there's no other way up to that balcony.' She might not have realised it, but she had just described the thief perfectly.
Then the inspector noticed a thin rope mark on the balcony rail. Someone must have used a rope, he thought; moreover, that person must have been both strong and light. Whereas an ordinary burglar would have struggled, this thief had moved like an acrobat.
The rope mark told its own quiet story. An untrained climber would have slipped on the icy rail; whereas a trained one could have moved up it silently and quickly. Moreover, the marks were smooth and even, which suggested calm confidence rather than panic. Hale measured the distance from the balcony to the frozen ground below and shook his head. An ordinary teenager can't have made that climb, however brave or determined. Whoever had done it must have practised the movement hundreds of times before, until it felt as natural as walking to the bus stop.
Hale remembered a useful piece of evidence: Mr Vance's young nephew had once worked in a circus. The nephew had claimed to be asleep upstairs, but he might have lied. Since the rope was still slightly warm from friction, the theft could only have happened minutes earlier.
The nephew, Daniel, was only sixteen, but he had grown up travelling with a small circus before his family finally settled down in the town. At his new school he still trained with the gymnastics club every single afternoon, and only the week before he had proudly posted a video of himself climbing a rope to the gym ceiling in under ten seconds. 'You must be rather proud of a skill like that,' Hale said gently. Daniel shrugged and stared at the floor. Since the boy clearly had the ability, the knowledge of the house and no proper alibi, the inspector was now almost certain. He thought to himself that he couldn't have invented a more obvious suspect even if he had tried.
'You can't have slept through this,' Hale told the nephew quietly. 'You must have known exactly where the safe was.' The young man turned pale. Although he said nothing, his face had already confessed.
Later that night, the missing necklace was found hidden inside a hollow gym trophy in Daniel's room, exactly where a clever teenager might have assumed no adult would ever bother to look. He never actually said the words 'I took it'; nevertheless, everyone standing in the room understood the truth. Mr Vance, although still furious, agreed not to call the police as long as the boy returned everything and promised to talk honestly with a counsellor at school. As Hale finally packed away his notebook, he allowed himself a small smile. The locked door had seemed impossible at first, yet in the end the answer had been hanging quietly in the freezing air, on one thin, still-warm rope, all along.
Choose the correct answer.
Are these sentences true or false, according to the text?
Complete each sentence with ONE word from the text. Mind the deduction structure (modal + have + V3).
Write your answer in your own words. These questions are not marked automatically.
1. Why was Hale sure that the necklace had been stolen, even though the door was locked?
2. How did the rope mark help Hale work out what kind of person the thief was?
3. Do you think Hale had enough evidence to be certain? Why or why not?
Find these connectors in the text — each one appears at least once: however, therefore, nevertheless, although, whereas, moreover, since, yet. (You will use these same connectors in the Writing section.) Note them down, then check.
Todd talks to Abidemi about life with an Inuit community in northern Canada: food, games and music.
You will hear a conversation: Todd asks Abidemi about living with the Inuit in the far north of Canada — the food they eat, the games they play and their music. You will listen TWICE. First listen: answer questions 1-5. Second listen: answer questions 6-10. (Kaydı İKİ kez dinleyeceksin: ilk dinlemede 1-5, ikinci dinlemede 6-10.)
Write and submit your account; your teacher will review it.
At B1 you linked ideas with and, but, so, because. At B2 you sound noticeably more advanced when you use formal, precise connectors. Four of them are essential this unit — and two familiar ones, although and however, become sharper tools.
| Connector | Use it to... | Example |
|---|---|---|
| moreover | add a stronger, extra point | The door was locked. Moreover, the window was shut. |
| therefore | show a logical result | There were no keys; therefore, someone must have climbed in. |
| whereas | contrast two ideas directly | I suspected the neighbour, whereas my brother blamed a stranger. |
| nevertheless | say "in spite of that" | Nothing was missing. Nevertheless, it felt suspicious. |
| although | concede a point inside one sentence | Although the door was locked, the necklace had vanished. |
| however | contrast between two sentences | He denied it. However, the evidence proved otherwise. |
See the difference — the same facts, written two ways:
| Basic linking ✗ | Confident B2 writing ✓ |
|---|---|
| The money was gone. The door was locked. Nobody came in. I thought about it. I found the answer. | The money had vanished, although the door was still locked. Therefore, I studied every clue. Whereas the others assumed a thief, I concluded that it must have been an inside job; moreover, the evidence proved me right. |
A "mystery" paragraph has three parts. The skeleton stays the same — you change the content, not the structure:
| Part | What to write | Example |
|---|---|---|
| 1. Opening | Set the scene: what strange thing happened | One morning we found the back door wide open. |
| 2. Body | Present the clues and your deductions. Use must have / can't have / might have + V3 to say how sure you are. Link with B2 connectors. | Nothing valuable had vanished; therefore, a thief can't have been inside. |
| 3. Closing | Reveal or reflect on what you finally concluded | In the end, it must have been the neighbour's dog. |
Write about a strange event or a small mystery from your own life — something disappeared, something unexpected happened, and you had to work out why. Use the past modals of this unit.
Değerlendirme öğretmenin tarafından yapılacak. (Your teacher will evaluate your writing.)
Mixed questions from the whole unit, then check what you can do.
14 questions: grammar + vocabulary + reading + listening. Each question is marked instantly.
Tick what you can do now. Honest answers help your teacher.
İşaretlemediğin madde varsa ilgili bölüme dönüp tekrar çalış — soldaki menüden her bölüme geri dönebilirsin.
Oturum kontrol ediliyor...