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Joy English · Level C1 · Modal verbsjoy-english.com

Modal perfects: speculating about the past

Name:Date:

Use must have, can't have, might have and should have to judge past events with the right degree of certainty.

Choose the correct form

Choose the option that best completes each sentence.

  1. The lights are off and the door is locked, so they ___ gone home.
    • a) needn't have
    • b) would have to
    • c) must have
    • d) can have
  2. That ___ been Kofi you saw at the station; he is in Madrid this week.
    • a) must have
    • b) can't have
    • c) needn't have
    • d) should have
  3. I'm not sure where Ana is. She ___ stuck in traffic.
    • a) couldn't have been
    • b) must have to be
    • c) might have been
    • d) can't be being
  4. You ___ a taxi; I would have collected you from the airport.
    • a) can't have taken
    • b) couldn't have taken
    • c) mustn't have taken
    • d) needn't have taken
  5. The courier said the parcel ___ arrived by Friday, but it hasn't.
    • a) should have
    • b) must have
    • c) can't have
    • d) couldn't have
  6. She looked exhausted. She ___ for hours.
    • a) must be worked
    • b) can have been worked
    • c) must have been working
    • d) must have worked being
  7. I wonder why Dev didn't answer. He ___ the phone ringing.
    • a) can't have been hearing
    • b) may not have heard
    • c) mustn't hear
    • d) might not heard
  8. The bridge ___ built before 1900; the style is far too modern.
    • a) must have been
    • b) should have been
    • c) needn't have been
    • d) can't have been

Complete the sentences

Type the correct modal perfect form of the verbs in brackets. The first word in brackets is the modal to use.

  1. Her name is on the list, so she ___ (must / see) the email.
  2. He is very reliable; he ___ (can't / forget) the deadline.
  3. My keys are missing. They ___ (might / fall) out of my pocket.
  4. The hotel is now full. We ___ (should / book) earlier.
  5. We have enough food for ten people. We ___ (needn't / bring) so much.
  6. Their coats were soaked. They ___ (must / wait) outside for hours.
  7. Perhaps the contract was signed last week. It ___ (may / sign) last week.
  8. She arrived late, so she ___ (can't / catch) the earlier bus.

Answer key

Choose the correct form

  1. c) must haveThe evidence makes it almost certain, so we use must have gone.
  2. b) can't haveWe are sure it was impossible, so we use can't have been.
  3. c) might have beenThe speaker is uncertain, so might have been expresses a possibility.
  4. d) needn't have takenThe taxi was unnecessary, so needn't have taken is right. The other options make no sense with I would have collected you.
  5. a) should haveShould have arrived expresses an expectation that was not met.
  6. c) must have been workingA logical deduction about a longer past activity uses must have been + -ing.
  7. b) may not have heardMay not have heard expresses a possible past event. The other options are ungrammatical or illogical.
  8. d) can't have beenThe modern style makes it impossible, so we use can't have been built.

Complete the sentences

  1. must have seenA strong deduction about the past needs must have + past participle.
  2. can't have forgotten / cannot have forgotten / couldn't have forgotten / could not have forgottenWe are sure it did not happen, so can't have forgotten (or couldn't have forgotten).
  3. might have fallen / may have fallen / could have fallenA possibility about the past uses might have + past participle; may and could are also correct.
  4. should have booked / ought to have bookedShould have booked expresses a regret about something we did not do.
  5. needn't have brought / need not have broughtNeedn't have brought means it was done but was unnecessary.
  6. must have been waiting / must have waitedA deduction about a longer past activity is best expressed with must have been + -ing; must have waited is also correct.
  7. may have been signed / might have been signed / could have been signedThe contract receives the action, so we need the passive: may have been signed.
  8. can't have caught / cannot have caught / couldn't have caught / could not have caughtHer late arrival makes it impossible, so can't have caught is correct.

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