Deduction & Speculation Exercises
Online exercises on modals of deduction and speculation — must be, can't be, could be, might be, and may be — with answers and explanations. Practise modal verbs of probability and certainty for present and past deduction, including past modals of probability such as must have, can't have, and could have + past participle. Multiple choice questions, worksheets, and printable PDF exercises from B1 to B2. 5 exercise sets with 100 questions (B1 - C1 Level).
Deduction & Speculation exercises: choose your exercise set
Start with Multiple Choice to build confidence with Deduction & Speculation exercises, or try Worksheet to practice all questions on one page.
Prefer to read first? Learn Deduction & Speculation
Must & Can't: Present Deduction Exercises
Deduction & Speculation Exercises
The Certainty Scale: Must, May, Might, Could & Can't Exercises
Deduction & Speculation Exercises
Speculation About the Present: Must Be, Can't Be & Might Be + -ing Exercises
Deduction & Speculation Exercises
“The office light is on and I can hear typing. Someone ___ in there.”
$24 billed yearly, or $3.99/month · cancel anytime
B1 ReadingNEWHuman Guides Take Waldrapp to Spain
Fifteen ibises reached northern Spain with human guides. A small plane brought the birds from Austria. They are at Alt E…
Past Deduction & Probability: Must Have, Can't Have & Could Have Exercises
Deduction & Speculation Exercises
“The streets are wet this morning. It ___ during the night.”
$24 billed yearly, or $3.99/month · cancel anytime
B2 ReadingNEWGuides Fly Fifteen Waldrapp Birds to Spain
Fifteen Waldrapp birds now live with a larger group in northern Spain. Guides helped the birds travel the route out of A…
Advanced Speculation: Must Have Been Doing & Complex Modal Deduction
Deduction & Speculation Exercises
“When I got home at midnight, the kitchen was a mess — flour everywhere, dirty bowls in the sink, and the oven was still warm. Someone ___ all evening.”
$24 billed yearly, or $3.99/month · cancel anytime
C1 ReadingNEWHuman Guides Fly Fifteen Rare Ibises to Spain
Fifteen northern bald ibises have joined a growing flock in northern Spain after human guides helped them along the rout…
Why practice Deduction & Speculation exercises?
These exercises help you master modals of deduction and speculation in English. Start with must and can't to make strong deductions about the present — drawing logical conclusions from evidence and clues at B1 level. Then learn to use the full certainty scale from must (almost certain) through may, might, and could (possible) to can't (impossible). Next, practise speculating about what is happening right now using must be, can't be, and might be + -ing. Finally, take on advanced past probability and past deduction exercises with must have, can't have, and could have + past participle to draw conclusions about what happened in the past at B2 level.