Perfect Infinitive With Modals Exercises (B1-B2)

⏱ Time: 07:30 📝 Questions: 15 📊 Level: B1, B2 📚 Type: Grammar ⭐ XP: up to +16 (on pass)

Can you use Perfect Infinitive With Modals correctly in everyday English? These 15 practice questions for Level B1-B2 go beyond memorisation — they put grammar concepts into realistic sentences and situations. Detailed explanations help you understand not just the what, but the why.

⏱ You have 07:30 to answer 15 questions. The timer only starts when you click Begin.

Q1  15
Q1 15

Question 1: The keys are not on the table. I ___ them in my coat pocket.

Question 1 options
'must have left' is correct because we use 'must have + past participle' to express a confident deduction about something that happened in the past. 'must leave' is present/future, 'must left' is grammatically incorrect, and 'must had left' is not a valid modal structure.
Q2 15

Question 2: You ___ told me the meeting was cancelled! I drove all the way there for nothing.

Question 2 options
'should have told' is correct because 'should have + past participle' expresses that something was desirable or necessary but did not happen. 'should tell' is present/future, 'should told' omits 'have', and 'should has told' is grammatically incorrect.
Q3 15

Question 3: The structure 'modal + have + past participle' is used to talk about situations in the past.

Question 3 options
True because the perfect infinitive ('have + past participle') after a modal verb always refers back to a past situation, whether expressing deduction, regret, possibility, or obligation.
Q4 15

Question 4: What does the sentence 'She can't have finished the exam already — it only started ten minutes ago' express?

Question 4 options
'can't have + past participle' is used to express a near-certain negative deduction about a past event based on present evidence. It does not express regret, permission, or future possibility.
Q5 15

Question 5: Arrange the words to make a correct sentence:

Question 5 options
  • again
  • He
  • forgotten
  • might have
  • his password

Drag items or use arrows to arrange them in the correct order.

The correct order is 'He might have forgotten his password again' because 'might have + past participle' expresses a past possibility, and the adverb 'again' follows the object.
Q6 15

Question 6: Which sentence is grammatically correct?

Question 6 options
'You needn't have bought so much food' is correct because 'needn't have + past participle' expresses that a completed action was unnecessary. The other options use incorrect forms: 'needn't bought' omits 'have', 'needn't has bought' is wrong modal agreement, and 'needn't have buy' uses the base form instead of the past participle.
Q7 15

Question 7: A: 'Why is Mark not at the office today?' B: 'I'm not sure. He ___ sick — he didn't look well yesterday.'

Question 7 options
'may have fallen' is correct because 'may have + past participle' expresses uncertainty about whether something happened in the past. The context shows the speaker is not sure, so a possibility modal is needed. 'must have fallen' would mean near-certainty, 'should have fallen' implies obligation, and 'would have fallen' requires a conditional clause.
Q8 15

Question 8: Which sentence correctly uses 'could have' to talk about an unrealised past ability or opportunity?

Question 8 options
'You could have asked for help instead of struggling alone' correctly uses 'could have + past participle' to express that an opportunity existed in the past but was not taken. The other options either use incorrect form ('could has asked'), a present base form ('could ask yesterday'), or mix 'could' with a conditional structure incorrectly.
Q9 15

Question 9: Put the words in the correct order:

Question 9 options
  • informed
  • us
  • about the delay
  • ought to have
  • They

Drag items or use arrows to arrange them in the correct order.

The correct order is 'They ought to have informed us about the delay' because 'ought to have + past participle' expresses an unfulfilled duty, and the object follows the main verb.
Q10 15

Question 10: The baby is asleep, but the front door is wide open. Someone ___ left it open by mistake.

Question 10 options
'must have left' is correct because the visible evidence (open door) leads to a confident deduction about a past action. 'might have left' would express mere possibility without confidence, 'should have left' expresses obligation, and 'would have left' requires a conditional context.
Q11 15

Question 11: Which statement about 'needn't have + past participle' is true?

Question 11 options
'needn't have + past participle' means the action WAS completed, but it was not necessary. It does not mean the action was refused, forbidden, or will happen in the future.
Q12 15

Question 12: He failed the exam even though he studied. → If he had studied harder, he ___ the exam.

Question 12 options
'would have passed' is correct because this is a third conditional sentence expressing an imagined different outcome in the past. 'would pass' is second conditional (present/future), 'would have pass' omits the past participle, and 'will have passed' is future perfect, not conditional.
Q13 15

Question 13: Match each sentence to the correct grammar label.

Question 13 options
She must have taken the last bus home.
He shouldn't have shouted at his colleague.
They might have arrived early before we got there.
I would have called you if I had known you were ill.
Undesirable action that was completed
Confident deduction about the past
Uncertain past possibility
Third conditional: unrealised past outcome

Select an item on the left, then tap its match on the right.

'Must have + past participle' = confident past deduction; 'Shouldn't have + past participle' = undesirable completed action; 'Might have + past participle' = uncertain past possibility; 'Would have + past participle' = third conditional unrealised past outcome.
Q14 15

Question 14: 'Might have + past participle' and 'must have + past participle' can be used interchangeably when expressing a past deduction.

Question 14 options
False because 'must have + past participle' expresses a strong, near-certain deduction, while 'might have + past participle' expresses a weaker, uncertain possibility. They are not interchangeable.
Q15 15

Question 15: Which sentence most naturally expresses that something was done but was completely unnecessary?

Question 15 options
'You needn't have prepared so much food — only three people came' uses 'needn't have + past participle' to show the action (preparing food) happened but was not necessary. 'Shouldn't have prepared' would imply it was wrong or undesirable, not merely unnecessary.