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Grammar Worksheet

Must and Have To: Obligation

A2–B1 must, have to, do not have to, must not
Explanation

Use must and have to for obligation: something is necessary.

Use do not have to when something is not necessary.

Use must not when something is not allowed. This is different from do not have to.

Form
MeaningFormExample
necessarymust / have to + base verbYou must wear a seat belt.
not necessarydo not have to + base verbYou do not have to bring food.
not allowedmust not + base verbYou must not smoke here.

Have to changes with the subject: She has to leave early.

Questions usually use have to: Do we have to pay?

Examples
  1. Students must arrive on time.
  2. I have to finish this today.
  3. She has to wear a uniform.
  4. You do not have to come if you are ill.
  5. We must not use phones during the exam.
  6. Do you have to work on Saturday?
  7. He does not have to cook tonight.
  8. Visitors must show ID.
Common Mistakes
Exercises
1 Choose the meaning

Write N for necessary, O for optional, or F for forbidden.

  1. You must show your passport.
  2. You do not have to book in advance.
  3. You must not park here.
  4. She has to take medicine twice a day.
  5. We do not have to wear shoes inside.
2 Correct the mistake

Each sentence has one mistake. Write the correct sentence.

  1. She have to study tonight.
  2. Do we must bring a book?
  3. You do not must wait outside.
  4. You must not pay means it is free if you want.
3 Complete the rule

Use must, must not, have to, has to, or do not have to.

  1. At the airport, you show your passport.
  2. In our class, students use phones during tests.
  3. Tomorrow is Sunday, so I get up early.
  4. My brother wear a uniform at school.
  5. we finish this today?
4 Rewrite with the same meaning

Use the word in brackets.

It is necessary to be quiet. (must)  →  You must be quiet.

  1. It is not necessary to bring lunch. (have to)
  2. Smoking is forbidden. (must)
  3. It is necessary for Ana to call her boss. (has to)
  4. Is it necessary for us to pay now? (have to)
5 Class rules

Write rules for a classroom, library, or sports club.

  1. You must ...
  2. You must not ...
  3. You have to ...
  4. You do not have to ...
Speaking Activity

Explain rules in different places.

Correct your partner if must not and do not have to are confused.