Grammar ~54 min of the core left

Make a guess

After this lesson you can

I can guess what is happening and say how sure I am.

Start the lesson Core 54 min · steps: 6 · optional: +2

Declared core time. Two of the core blocks carry no figure at all, so the real lesson is longer than this sum.

Grammar

15 min

You know these verbs in other meanings: must — obligation (A2 #10), can — ability (A1 #20), could — a polite request (A2 #17). They have a second meaning too: they show how sure the speaker is about a guess. A light in the window, a car outside the house, a person who doesn't answer the phone — and we come to a conclusion.

The scale of certainty:

how sure example
is I know for certain He is at home — I can see him.
must almost sure: yes He must be at home — his car is outside.
may / might / could perhaps: yes He might be at the gym.
may not / might not perhaps: no He might not be at home.
can't almost sure: no He can't be at work — it's Sunday.
isn't I know for certain: no He isn't here.

The form. After the modal verb comes the base form without to, and the modal itself has no -s: She must be tired, He might know. If the guess is about what is happening right now, use be + -ing: He must be working late — the light's on in his office. They might be waiting for us outside.

How to choose.

must is a conclusion from evidence: I have put the facts together and see no other explanation. The evidence is usually named next to it: You must be hungry — you haven't eaten all day. But must does not mean "for certain". If you know for sure, no modal verb is needed: He's at home — I've just spoken to him. must says "this is my conclusion", and the listener hears that it is a conclusion, not a fact. Many languages give this meaning with a separate word, such as French sûrement or German bestimmt; in English the verb itself does the job.

may, might, could give one possible explanation, and I don't know if it is right. There is almost no difference between them: might is a little less sure, may a little more formal, could means "it is quite possible": It could be a virus.

can't is a conclusion "no": the facts make the explanation impossible. That can't be Tom — he's in Spain this week.

The negative is can't, not mustn't. mustn't is a prohibition (A2 #10): You mustn't park here. For "almost certainly not", British English says can't. And might not is a soft "perhaps not": She might not know about the meeting.

A question. A question about a guess takes could or can: Could it be a mistake? — "is it possible that it's a mistake?" Who can that be? — "I have no idea who it is — who is it?" With must and might such questions are almost never made.

must — a guess or an obligation? Look at the verb after it. With be, know, have in the meaning "own" and with the continuous form, must is almost always a guess. With an action, it is an obligation:

You must be tired. I think you are tired. — a guess
You must go to bed. It is necessary for you to go to bed. — an obligation

maybe and may be. maybe is one word, an adverb, and usually goes at the start: Maybe he's at home. may be is two words, the modal verb and be, and goes after the subject: He may be at home. The meaning is the same, but they are written differently.

More examples:

That must be the postman. I'm almost sure it's the postman.
She might be in a meeting. Perhaps she's in a meeting.
This can't be our bus — ours is number twelve. It's impossible that this is our bus.
He must know the answer — he's a doctor. I'm almost sure he knows the answer.
You could be right. Perhaps you are right.

Don't say this. ✗ He mights be ill → ✓ He might be ill. A modal verb does not change with the person; it never has -s.

Check yourself. Your neighbour's car is outside his house, and the lights are on. What do you say: He must be at home or He might be at home? How do you say that you are almost sure something is not true? What is the difference between Maybe she's ill and She may be ill?

show the answers
He must be at home — the evidence fits together; That can't be true (or It can't be true); there is no difference in meaning: in the first, maybe is an adverb, in the second, may be is the modal verb with be.
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Common learner errors

written for your language
1

mustn't in a guess

He mustn't be at home sounds to a British listener like a prohibition: "he is not allowed to be at home". For "almost certainly not at home" you need ✓ He can't be at home. French il ne doit pas être chez lui, Spanish no debe de estar en casa and Italian non deve essere a casa are guesses, and learners translate them with mustn't. In English the negative guess goes with can't.

2

can for "perhaps"

It can be a virus does not mean "perhaps it's a virus". In a positive sentence can talks about what is possible in general, not about this one case. For a guess you need ✓ It could be a virus / It might be a virus. French ça peut être, Spanish puede ser and Portuguese pode ser point to can. Only in a question (Who can that be?) and with can't does can make a guess.

3

A guess about now without -ing

The light's on in his office — he must work late sounds like an obligation ("he has to work late") or a habit, not a guess about this evening. For what is happening right now you need ✓ He must be working late. German and French have no continuous tense of their own, so learners leave the verb in the simple form.

4

must about the future

He must come tomorrow is about an obligation: "he has to come". French il doit venir demain means "he is expected to come tomorrow", and learners carry it over with must. For a guess about the future — ✓ He'll probably come tomorrow or He might come tomorrow: a guess with must is almost always about the present.

Pronunciation

4 min

The stress is on the modal verb: it carries the meaning of the guess. He MUST be at home, That CAN'T be right, She MIGHT be ill. The be after it is unstressed and short — /bi/.

must be — /ˈmʌs bi/: the /t/ between /s/ and /b/ drops out. The same in must know /ˈmʌs nəʊ/.

can't in a guess is full and long — /kɑːnt/. The final /t/ before a consonant almost disappears, and then only the long /ɑː/ and the stress tell can't from can (A1 #20). might be — /ˈmaɪt bi/: the /t/ is not released, it only cuts the vowel short.

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Text

5 min

Have you seen Tom this morning?

No, but he must be somewhere in the building. His coat's on his chair, and his computer is on.

And his coffee is still warm. He can't be far away.

He might be in the meeting room. The managers meet there on Thursdays.

It can't be the managers' meeting. That always starts at ten, and it's only half past nine.

Then he could be at the coffee machine. Or he may be down in IT — his laptop stopped working yesterday.

Wait, his phone's here too. He never goes anywhere without his phone. He must be very close.

Listen. Can you hear that? Somebody's singing in the kitchen.

That can't be Tom. He hates singing.

Hang on — isn't it his birthday today? Maybe they're singing to him.

Of course! That must be why there's a cake on the kitchen table. They must be waiting for us. Come on!

Reading aloud

Exercises

30 min

1. Gap fill.

  1. His car is outside, so he be at home. (almost sure: yes)
  2. That be right — the bill says £300 for two coffees. (almost sure: no)
  3. She isn't answering. She be in a meeting. (perhaps)
  4. You've been working for ten hours. You be exhausted. (almost sure: yes)
  5. This be Anna's bag — it has her name on it. (almost sure: yes)
  6. He be at work — it's Sunday, and his office is closed. (almost sure: no)
  7. Take an umbrella. It rain later. (perhaps)
  8. They be asleep — the lights are on, and I can hear music. (almost sure: no)
  9. Listen to her accent. She be from Scotland. (almost sure: yes)
  10. I'm not sure where Lucy is. She be in the library. (perhaps)
Show the answers
must; can't; might / may / could; must; must; can't; might / may / could; can't; must; might / may / could

2. Rewrite with a modal verb.

  1. I'm sure he's at home.
  2. Perhaps she's ill.
  3. I'm sure it isn't true.
  4. Perhaps they know the answer.
  5. I'm sure you're tired after the flight.
  6. I'm sure that isn't our train — ours leaves at six.
  7. Perhaps he doesn't know about the party.
Show the answers
He must be at home; She might be ill / She may be ill / She could be ill; It can't be true; They might know the answer / They may know the answer / They could know the answer; You must be tired after the flight; That can't be our train — ours leaves at six; He might not know about the party / He may not know about the party

3. Expand the prompt into a guess

  1. The light is on in his office. (he / must / work / late)
  2. She isn't answering her phone. (she / might / drive)
  3. I can hear water in the bathroom. (someone / must / have / a shower)
  4. They aren't in the classroom. (they / could / wait / outside)
Show the answers
He must be working late; She might be driving; Someone must be having a shower; They could be waiting outside

4. Error correction.

  1. May be he's still at work.
  2. She must to be tired after the trip.
  3. He mights be at the gym.
  4. It maybe a mistake.
  5. That can't is Tom — he's in Spain.
Show the answers
Maybe he's still at work / He may still be at work; She must be tired after the trip; He might be at the gym; It may be a mistake / Maybe it's a mistake; That can't be Tom — he's in Spain

5. Matching.

  1. She's yawning.
  2. People are carrying umbrellas.
  3. Nobody's answering the door.
  4. The shop is dark.
  5. He knows everything about cars.
Show the answers
`She's yawning.` — `She must be tired.`; `People are carrying umbrellas.` — `It must be raining.`; `Nobody's answering the door.` — `They might be out.`; `The shop is dark.` — `It must be closed.`; `He knows everything about cars.` — `He must be a mechanic.`

6. Make three guesses of different certainty

about each situation. The answers below are an example. 1) A colleague hasn't come to work and isn't answering the phone. 2) For an hour there has been a loud knocking noise in the flat above you.

Show the answers
He might be ill. He could be stuck in traffic. He can't be on holiday — he was here yesterday; They must be doing some repairs. They might be putting up shelves. They can't be asleep

7. Say it in English.

Each line describes a situation in simple words. Say it in one sentence, with the modal verbs of this lesson. 1) You are almost sure that he is at home. The reason: his car is outside. 2) You are almost sure that something is not true. 3) Perhaps she is in a meeting — you don't know. 4) You and a friend are late. You are almost sure that right now your other friends are outside, waiting for the two of you. 5) Someone has just had a long flight. You are almost sure they are tired. Say it to them.

Show the answers
He must be at home — his car is outside; That can't be true / It can't be true; She might be in a meeting / She may be in a meeting / She could be in a meeting / Maybe she's in a meeting; They must be waiting for us outside; You must be tired after the flight
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Summary

Covered: the scale of certainty must — may, might, could — can't, a guess about what is happening now (must be doing), the negative with can't and might not, a question with could, must as a guess and as an obligation, maybe against may be. Next — lesson 11: obligation and ability.

End of the core

The lesson counts as done once the exercises are done. Everything after this is optional.

Lesson 83

optional

Vocabulary for your deck

16 words
  • somewhere /ˈsʌmweə/ in some place
  • far away /ˌfɑːr əˈweɪ/ at a long distance
  • meeting room /ˈmiːtɪŋ ruːm/ a room in an office where people have meetings
  • warm /wɔːm/ a little hot, in a nice way
  • hang on /ˌhæŋ ˈɒn/ wait a moment (informal)
  • cake /keɪk/ a sweet food made from flour, eggs, sugar and butter
  • postman /ˈpəʊstmən/ a person who brings letters to people's homes
  • mistake /mɪˈsteɪk/ something that is not correct
  • bill /bɪl/ a piece of paper that shows how much you must pay, for example in a restaurant
  • exhausted /ɪɡˈzɔːstɪd/ very tired
  • asleep /əˈsliːp/ sleeping
  • accent /ˈæksənt/ the way people from a certain place pronounce words
  • yawn /jɔːn/ to open your mouth wide because you are tired
  • mechanic /məˈkænɪk/ a person whose job is to repair cars and machines
  • stuck in traffic /ˌstʌk ɪn ˈtræfɪk/ not able to move because there are too many cars on the road
  • gym /dʒɪm/ a place where people go to do sport and exercise

Writing

Five or six sentences: you have come home, the door isn't locked, there is someone else's bag on the table, and music is playing in the kitchen. Make guesses of different certainty.

Example

The door is open, and there's music in the kitchen. Someone must be at home. It can't be my flatmate — she's in Paris this week. It might be my brother; he has a key. This bag on the table must be his — it's the same colour as his old one. He could be cooking: I can smell onions. Or he might be waiting to surprise me.

Checklist

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Practise this lesson in the other sections

Dictationbased on this lesson Write down what you hear. The check shows every word that differs, and how. Write the dictation Reading aloudbased on this lesson Read the lesson text aloud — speech recognition highlights the words it did not catch. Read the text aloud Reading and listeningA1–C1 Texts at every level with comprehension questions; the transcript opens after you answer. Try it

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