Study the rules, look at the examples, then do the exercises.
Sometimes we know a fact for certain: "It is raining." But very often in real life we are not sure, and we need to say how likely something is. Is it certain? Is it just possible? Is it impossible? English uses a small group of modal verbs to show exactly how confident we are.
In this unit you will learn the modals of possibility and deduction: may, might and could (possible), must (I'm almost sure it is true), and can't (I'm almost sure it is impossible). Choosing the right one is one of the most useful speaking skills at B1.
Modals are easy to build. After the modal, we always use the base verb (the infinitive without to). The modal never changes for the subject — there is no -s in the third person, and we never add do / does.
| Subject | Modal | Base verb | Example |
|---|---|---|---|
| I / you / we / they | may / might / could | be, rain, know | They might know the answer. |
| he / she / it | may / might / could | be, rain, know | She could be right. |
| it (deduction) | must / can't | be, mean | It must be a mistake. |
To say that something is possible now or possible in the future, we use may, might or could. In most everyday sentences the three are almost the same in meaning — each one means "perhaps".
| Modal | Meaning | Example |
|---|---|---|
| may | perhaps (a little more formal) | It may rain this afternoon. |
| might | perhaps (very common in speech) | She might be at home now. |
| could | perhaps (one of several options) | He could be right — I'm not sure. |
This is the heart of the unit. Think of a "certainty line". At one end you are sure something IS true; at the other end you are sure it is NOT true. The modal you choose shows exactly where you are on that line.
| How sure? | Modal | Example |
|---|---|---|
| 100% sure it is true | must | She must be exhausted. |
| Maybe true (about 50%) | may / might / could | She might be exhausted. |
| Maybe not true | may not / might not | She might not be exhausted. |
| 100% sure it is impossible | can't | She can't be exhausted — she slept all day! |
Be careful: there are two ways to be negative, and they mean very different things. May not / might not means "perhaps not". Can't (or couldn't) means "impossible" — much stronger.
| Form | Meaning | Example |
|---|---|---|
| may not / might not | it is possible that it is NOT true | He might not come to the party. (Maybe he won't.) |
| can't / couldn't | it is impossible / I'm sure it is not true | He can't be at the party — he is in Paris! (Impossible.) |
When we look at the evidence and reach a confident conclusion, we use must (I'm sure it is true) or can't (I'm sure it is not true). This is called deduction. Notice: can't is the negative of must here — not "mustn't".
| Evidence | Conclusion | Example |
|---|---|---|
| The lights are on and I can hear music. | must (positive) | Someone must be at home. |
| It's midnight and every window is dark. | can't (negative) | They can't be awake now. |
| He hasn't eaten since morning. | must (positive) | He must be really hungry. |
These are the errors B1 students make most often with modals of possibility. Check your own sentences against this list.
| Wrong ✗ | Right ✓ | Why? |
|---|---|---|
| It can rain later, take a coat. | It might rain later, take a coat. | for possibility in a statement we use may/might/could, not "can". |
| She mights be at school. | She might be at school. | no -s and no "to" after a modal. |
| He must to be tired. | He must be tired. | modal + base verb, never "to". |
| That mustn't be true. | That can't be true. | negative deduction uses can't, not mustn't. |
| They can be Turkish, I'm not sure. | They could be Turkish, I'm not sure. | uncertain guess → may/might/could. |
Two friends see a new face in the school corridor and try to work out who he is. Read it twice and notice how they move along the "certainty line" — from a wild guess, to a possibility, to a confident conclusion.
Choose the correct answer. — 10 questions, each one is marked instantly. Questions get harder as you go.
Learn the words, then use them to speculate about the world around you.
Write 8 sentences in which you speculate about people or situations. 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 text, 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): possible · possibility · perhaps · certain · clue · evidence · obvious · probably · likely
Aylin loved a good mystery. She and her friends spent many afternoons reading detective stories, watching crime series, and trying to guess the ending long before the final scene. 'A real detective never panics,' she liked to tell them. 'You just look carefully at the clues, think about everything that is possible, and stay calm until you know the truth.' Her friends often teased her about this, but they secretly admired how she noticed small details that other people always seemed to miss. Aylin never imagined that she would need her detective skills on an ordinary Monday, before the first lesson of the week had even begun.
When Aylin arrived at school on Monday morning, something was strange. The lights in her classroom were on, but nobody was there. Her friend Berk's jacket was hanging on his chair, and a cup of tea sat on his desk. However, Berk himself was nowhere to be seen.
'This is very odd,' Aylin thought. 'Berk is always at his desk before the first lesson. He can't be far away, because his jacket and tea are still here.' She touched the cup: it was still warm. 'He must be somewhere close,' she guessed.
Curious now, Aylin took out her phone and opened the class group chat. Almost everyone in her class posted there every morning — photos of last night's homework, news about the football and basketball teams, and short, funny videos that made the whole group laugh in the corridor. There was nothing new from Berk, but his last message, sent only a few minutes earlier, read, 'On my way, see you in class!' 'If he wrote that just now,' Aylin reasoned, 'he must have been here very recently. He might have stepped out for a moment, but he can't have gone home. Nobody sends a cheerful message and then disappears completely.' The more carefully she thought about it, the calmer she felt. There was surely a simple explanation, and a good detective, she reminded herself, never jumps to conclusions.
There were several possibilities. Perhaps Berk was talking to a teacher, or maybe he had gone to buy a snack. He might be in the library. It was also possible that he was simply in the corridor. Aylin was not certain, but she did not think anything was wrong.
As she waited by the window, Aylin remembered that Berk played for the school basketball team, and their morning practice sometimes ran a little late. 'Maybe the coach kept him behind to talk about Saturday's match,' she thought, 'or maybe he is helping in the music room again.' Berk was the kind of friend who could never say no when a teacher needed a hand. Only last week he had spent his entire break carrying chairs into the hall for the drama club, and he had missed half of his snack because of it. 'That could easily be it,' Aylin decided. 'He may be helping someone at this very moment.' Yet none of these ideas fully explained the warm tea and the jacket that had been left behind in such a hurry. A clue that did not fit, she knew, was always worth a second thought.
To be sure, Aylin walked quietly to the classroom door and looked out into the long corridor. A few younger students were hurrying to their lockers, and a cleaner was pushing a trolley near the stairs, but there was no sign of Berk anywhere. 'He isn't in the corridor, then,' she noted, crossing one possibility off her mental list. 'So he must be somewhere else in the building.' It felt good to remove even one wrong idea; each answer, she thought, brought her a little closer to the truth. That was the part of solving a mystery that she enjoyed the most.
Then she noticed a clue on the desk: a small note. It said, 'Back in 10 minutes.' Now the evidence was obvious. 'He can't be in trouble,' Aylin said to herself, feeling relieved. 'He probably just went to the canteen.'
While the ten minutes slowly passed, Aylin thought about how easily people worry over nothing at all. Only last term, the whole class had panicked when their teacher, Mr. Deniz, did not arrive for the lesson on time. Within minutes, everyone had convinced themselves that something terrible must have happened to him. In the end, he had simply been stuck in traffic on his way back from a school trip, and he walked in laughing at their worried faces. 'We always imagine the worst,' Aylin remembered with a smile, 'but the boring answer is nearly always the true one.' A good detective, she knew, does not guess wildly or frighten herself with impossible ideas; she waits patiently for real evidence before she decides what must be true and what simply cannot be.
Suddenly, the door opened and Berk walked in, carrying a large box. 'Sorry!' he said. 'Our teacher needed some new books from downstairs, so I went to carry them up.' Aylin laughed. The mystery was solved. Sometimes the simplest explanation is the likely one, and there is usually no need to worry.
Later that day, at lunch, Aylin told her friends the whole story, and they laughed together in the busy, noisy canteen. 'You should start a detective club!' said her friend Selin. 'You solved a mystery before nine o'clock in the morning.' Aylin grinned, but she knew the real lesson was a very simple one. When something looks strange, you do not need to imagine a disaster straight away. You look calmly at what you can actually see, you think about everything that is possible, and you wait for the one clue that finally tells you what must be true. 'Most mysteries at school,' she said, taking a bite of her sandwich, 'have wonderfully ordinary endings — and honestly, that is exactly why I enjoy them so much.'
Choose the correct answer.
Are these sentences true or false, according to the text?
Complete each sentence with ONE word from the text.
Write your answer in your own words. These questions are not marked automatically.
1. Why did Aylin decide that Berk "must be somewhere close"?
2. What possibilities did Aylin think of before she found the note?
3. Why do you think Aylin felt relieved when she read the note?
Find these connectors in the text — each one appears at least once: and, but, so, because, however, or, then. (You will use these same connectors in the Writing section.) Note them down, then check.
Todd and Sarah talk about how they react in different everyday situations.
You will hear two friends, Todd and Sarah, talking about what they do when they feel stressed, tired, bored or angry. 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 paragraph; your teacher will review it.
A list of short, separate sentences is not real writing. What connects your ideas is linking words. At A2 you used and, but, so, because. At B1 you add more powerful connectors: also, when, while, although and however. These let you show contrast, background and extra information like a confident writer — and they work perfectly when you speculate about a mystery.
| Connector | Use it to... | Example |
|---|---|---|
| and | add information | The door was open, and the lights were on. |
| but | show a small contrast | He might be here, but I can't see him. |
| so | show a result | The tea was warm, so he must be close. |
| because | give a reason | It can't be Ana because she is abroad. |
| also | add an extra point | He may be at lunch. He could also be upstairs. |
| when | say at what time | When I arrived, the classroom was empty. |
| while | two things at the same time | While I was thinking, the phone rang. |
| although | show a strong contrast | Although it looked strange, nothing was wrong. |
| however | contrast between two sentences | It might be serious. However, it was just a note. |
A "mystery" paragraph has three parts. The skeleton stays the same every time — you change the content, not the structure:
| Part | What to write | Example |
|---|---|---|
| 1. Opening | Describe the strange situation | Last week I found a mysterious box outside my door. |
| 2. Body | Speculate: list possibilities with may/might/could, then reach conclusions with must / can't. Link with connectors. | It might be a gift, but it can't be from Ali, because he is away. It must be from a neighbour. |
| 3. Closing | Say what happened, or what you still wonder | In the end, I still don't know who sent it. |
Imagine you receive a mysterious parcel with no name on it. Write about who it might be from and what could be inside. Speculate with modals of possibility.
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...