Grammar Time: Adjectives and Adverbs for Speculation

Specific modal verbs, adjectives and adverbs are used to introduce speculation and deduction. Let’s learn to use modal verbs, adjectives and adverbs for speculation.

Speculation is the act of guessing possible answers tp a question without having enough information to be certain.

Deduction is the process of reaching a decision or answer by thinking about the known facts.

Exam in Mind Level B1/B2

Modal Verbs for Speculation and Deduction

Must be – used to say you are sure that something is or was was true.

  • It must be difficult to drive in the busy streets in London (a present fact).
  • You must have been cold when you were in Finland in winter (a fact in the past).

Can’t be – something probably wasn’t true. Note: You cannot use mustn’t + verb as this is an order as in you mustn’t do that = you’re not permitted to do that.

  • It can’t be that cold, I saw a man in shorts (present).
  • It can’t have been difficult, you finished early (past).

May not be/ might not be – it is possible but with less certainty. We can also use might instead of may.

  • We may not be able to go there. It’s very expensive

Should be – a good probability

  • It should be fine, I just need to double check.

Adjectives and Adverbs for Speculation

You’re bound to be  – bound is an adjective which with the infinitive verb describes something that is almost certain to be true. You could also also use sure or certain.

  • You’re bound to be tired after all that exercise.
  • Peter is bound to / sure to lose his job, he’s been really disloyal to his boss.

It’s (very) likely that – it’s probable. Likely is an adjective despite the ‘ly’ suffix. You could also use the structure without ‘that‘ as in it’s likely you’d enjoy….which shows more clearly that ‘likely’ is an adjective.

  • It’s very likely that we’ll lose this match. We’re already losing 3-0.

be likely / unlikely + to + infinitive
be likely / unlikely + that + clause

  • Mary is likely to get the scholarship.
  • It’s unlikely that we will travel abroad in short time.

Likely is used to express probability, it has a similar meaning to probable and possible, whereas unlikely is used to express improbability. They are both placed before a verb in a sentence or between the auxiliary verb and the main verb:

  • She will likely lose weight. (= She will probably lose weight.)
  • She will unlikely lose weight. (= She won’t probably lose weight.)
  • Is it likely that you will cry when you see him?
  • They are likely to win the match.
  • You are unlikely to lose weight, you are eating too much.
  • It is unlikely that we will fall asleep.
  • I will likely fall ill as I am wearing thin clothing.
  • We will likely get angry when we see him.
  • This situation will unlikely change in the future. 
  • She will unlikely be bored at this party.

Definitely – certainly.

  • It’s definitely the best option

Definitely and probably are adverbs so they go:

  • before the main verb: They definitely / probably bought the house. 
  • between the auxiliary verb and the main verb: They will definitely / probably buy this house.
  • before the negative auxiliary verb (won’t, isn’t, shouldn’t, etc.): He definitely / probably won’t get the degree. If you don’t speak very slowly, they probably won’t understand you. But if we don’t use short forms, probably/definitely go after the auxiliary verb and before notIf you don’t speak very slowly, they will probably not understand you.
  • after the verb to be in positive sentences: Mary is definitely / probably John’s wife.
  • before the verb to be in negative sentences: The end of the quarantine isn’t definitely / probably next month.

Have practice using modal verbs, adjectives and adverbs for speculation and deduction.

Task 1. Answer the following questions using adjectives and adverbs for speculation (bound to, sure to, certain to, likely to, unlikely to, will definitely / probably, definitely / probably won’t).

  1. What will the weather be like tomorrow? For exampleIt is bound to be sunny. / It will probably rain. etc.
  2. What will you do on Friday evening?
  3. Will you pass your exams in May or June?
  4. I pay for renting a flat in Santander. Tell your partner about your obligations or frustrations.
  5. What are your plans for the summer?
  6. Will you watch the Oscars at the end of the month?
  7. Talk about a film that is on at the cinema these days. Will you go and see it?
  8. Will you go shopping next weekend?
  9. Will you study English tonight?
  10. Do you think you will ever study another language?

Task 2. Insert likely/unlikely, probable/probably, or possible into the sentences. Some sentences might have more than one option.

  1. The way he’s driving, he’s ______ to have an accident.
  2. It’s ______ going to rain so bring your umbrella.
  3. The pathologist quickly discovered the ______ cause of death.
  4. There were a number of ______ outcomes to be considered.
  5. It doesn’t seem ______ to climb such a sheer cliff.
  6. They’re the better side so they’ll ______ win. (ADVERB)
  7. I know you’re busy but can you ______ spare a few minutes? (ADVERB)
  8. In the ______ event of an emergency….” (NEGATIVE)

Task 3. Choose the correct answer to complete the sentences.

1.You ______ yourself when you attend the conference in Paris next week, so you should learn how to do so in French before going.

A. will probably have to introduce
B. could probably have to introduce
C. must probably introduce

2. If the package is to arrive on time, we ______ before the weekend.

A. will have to mail it
B. will probably mail it
C. couldn’t mail it

3. If you take the apartment, you ______ the rent at the start of each month.

A. will probably be responsible for paying
B. may have responsibility for paying
C. will be responsible for paying

4. It’s fortunate that you are here to give me a hand. Without your help, I ______.

A. couldn’t have finished on time.
B. have to finish on time.
C. probably won’t finish on time.

5. Wendy has a job interview tomorrow afternoon. I told her she______

A. will probably have to dress conservatively and be on time.
B. may have to dress conservatively and be on time.
C. will have to dress conservatively and be on time.

6. Jill hasn’t been feeling too well lately. She ______ the party on Friday night.

A. must not be able to attend
B. maybe not able to attend
C. may not be able to attend

7. You have some time to make up your mind about taking the job. You _______ until Friday.

A. don’t have to tell me your decision
B. didn’t have to tell me your decision
C. must tell me your decision

8. I’ve gained so much weight lately, my suit ______

A. will probably not fit.
B. couldn’t fit.
C. will have to fit.

9. PERSON A: Are you going to travel anywhere on your vacation? PERSON B: It all depends on airline prices. I ______

A. might
B. could have.
C. maybe.

10. Yesterday, I saw Ted looking at diamond rings in a jewelry store. In my opinion, he ______

A. might have to ask his girlfriend to marry him.
B. must be going to ask his girlfriend to marry him.
C. is going to ask his girlfriend to marry him.

Task 4. Likely or Unlikely?

  1. It is unlikely / likely that we get a cat. I’m allergic.
  2. You are unlikely / likelyto fall asleep early, I heard you were up till’ late last night.
  3. She is unlikely / likely going to become a linguist. She just loves languages.
  4. You are unlikely / likely going to pass that exam. You haven’t studied anything.
  5. I am unlikely / likely going to eat the cake. I’m very hungry.
  6. It’s unlikely / likely that we go on vacation in Greece this summer. We don’t have any money.

Task 5.  Complete the sentences with likely or probably.

  1. My mother’s ____________ to be in the garden watering the plants.
  2. I’ll ____________ be very busy tomorrow.
  3. The missing plane ____________ crashed in the sea.
  4. There’s ____________ to be a hurricane later this month.
  5. They aren’t very ____________ to raise our salary, are they?
  6. James will ____________ be late. He always is.
  7. I’m ____________ to be very busy tomorrow.
  8. The police say that the burglars were ____________ local people.

Task 6.  Rewrite these sentences changing from probably to likely or vice versa.

  1. It’s likely to snow tonight. – It will probably snow tonight.
  2. The builders probably won’t finish until the summer. – The buildres aren’t likely to finish until the summer.
  3. The meeting will probably finish late.
  4. The jury are likely to find him guilty.
  5. There will probably be a lot or traffic this evening.
  6. It’s likely that we’ll never know what really happened.
  7. We probably won’t be here at the weekend.