Definition / Explanation
Both must and have to talk about obligation. In simple explanations, must often shows that the speaker feels something is necessary, while have to often comes from a rule, timetable, or outside situation. In real life, the difference is sometimes small, but this contrast helps learners choose the form. Must is more common for strong personal rules or written instructions. Have to is very common in everyday speech.
Key Rules
- Use must + base verb: I must go now.
- Use have to + base verb: I have to work tomorrow.
- Must often feels more personal: I must remember her name.
- Have to often comes from rules, work, school, or situations: We have to wear a uniform.
- In negatives, mustn't means “do not do it”; don't have to means “it is not necessary.”
Examples
- I must go now.
- We have to wear badges at work.
- She has to get up early tomorrow.
- I must remember to call my mum.
- You don't have to come if you are busy.
Common Mistakes
- ❌ I must to go now. -> ✅ I must go now.
- ❌ She have to get up early. -> ✅ She has to get up early.
- ❌ We mustn't come if we are busy. -> ✅ We don't have to come if we are busy.
Tips
- Remember the difference: mustn't = not allowed, don't have to = not necessary.