Modal Verbs of Deduction: Must, Might, Cant

Lesson 9: Modal Verbs of Deduction (Must, Might, Can't).

1. Overview
Make logical guesses and deductions about situations based on evidence using modal verbs.

2. Levels of Certainty
- Must: You are almost 100% sure something is true (e.g., He worked all night; he must be tired).
- Might / May / Could: You think it is possible, but you are not sure (e.g., It might rain later today).
- Can't: You are almost 100% sure something is impossible (e.g., That can't be true; I just checked the logs).

3. Practice Exercise
Choose the correct modal verb (must, might, can't):
1. Look at the bright sun; it _____ rain today.
2. He has been coding for ten hours straight; he _____ be exhausted.