Modal Verbs of Obligation: Have To and Must

Lesson 6: Modal Verbs of Obligation (Have To and Must).

1. Overview
Express rules, duties, and things that are necessary to do using "have to" and "must".

2. Using "Must"
"Must" expresses a strong personal obligation or rule set by the speaker:
- I must finish this code today.
- You must wear a helmet.

3. Using "Have To"
"Have to" expresses an external obligation, rule, or routine:
- I have to work night shifts.
- She has to submit her assignment.

4. Negative Difference
- Mustn't means prohibition (don't do it).
- Don't have to means lack of obligation (it's optional).

5. Practice Exercise
Choose between "must" or "have to":
1. I _____ wake up early tomorrow for my shift.
2. You _____ touch exposed wires; it is dangerous.