WPWord Play

Modals of Deduction

LESSON
Lesson Reference
Grammar rules and examples for self-study
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REVIEW
Review Exercises
Fill-in and gap-fill practice tasks
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ANSWER KEY
Answer Key
Correct answers for all exercises
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Modals of Deduction

Grammar Reference

Form Example
must bealmost certain it IS trueHe knows everything — he must have studied a lot.
can't bealmost certain it IS NOT trueShe won — she must be very talented.
might/could bepossibleHe arrived in 5 minutes — he can't have taken the motorway.
Past deductionmodal + have + PPThat can't be her — she's in Tokyo.

Modals of Deduction — Exercises

Choose the correct modal

  1. She has won every competition this year. She must / can't / might be a very dedicated athlete.
    (must / can't / might) 
  2. He never recycles anything. He must / can't / might care much about the environment.
    (can't / must / might) 
  3. I am not sure where she is — she must / can't / might be at the departure lounge already.
    (might / must / can't) 
  4. That assignment is only two pages long. It must / can't / might have taken more than an hour to write.
    (can't / must / might) 
  5. The app has ten million downloads. It must / can't / might be very popular.
    (must / might / can't) 
  6. I haven't seen him all day — he could / must / can't be somewhere on campus.
    (could / must / can't) 
  7. She has been studying for twelve hours straight. She must / might / can't be exhausted.
    (must / might / can't) 
  8. A wildlife reserve that size must / might / can't be home to thousands of species.
    (must / might / can't) 

Write your own deductions

Write a sentence with must, might/could, or can't based on the evidence given.

  1. The athlete has broken three world records this year.
  2. He has never used a computer in his life.
  3. I'm not sure if the lecture has started yet.
  4. She scored 100% on every test this term.

Exercise 3 — Error Correction

  1. Find and correct the ONE error: "He must to be very tired after the long journey."
  2. Find and correct the ONE error: "She can't be at home — I can see her in the park."
  3. Find and correct the ONE error: "They should arrived by now."
  4. Find and correct the ONE error: "It might not to rain this afternoon."

Modals of Deduction — Answer Key

Choose the correct modal

  1. must
  2. can't
  3. might
  4. can't
  5. must
  6. could
  7. must
  8. must

Write your own deductions

  1. Sample answer: She must be in the best form of her life.
  2. Sample answer: He can't be very comfortable with technology.
  3. Sample answer: It might have started already — let's check.
  4. Sample answer: She must be a very talented student.

Exercise 3 — Error Correction

  1. —
  2. —
  3. —
  4. —