Mustn’t vs. Don’t have to – English Grammar Exercises for B1
Choose the best option (A, B, C, or D) to complete each sentence. Read the text carefully, as all questions are part of a continuous speech given by a teacher before a major exam.
“Good morning, class. Before we begin the final test, let me explain the rules and structure.”
1 To pass this exam, you ______ answer every single question on the paper; some of them are optional.
(a) mustn’t
(b) haven’t to
(c) don’t have to
(d) shouldn’t
2 However, remember the most important rule: you ______ talk to your classmates once the test begins.
(a) don’t have to
(b) mustn’t to
(c) don’t must
(d) mustn’t
3 In Section A, there are 12 multiple-choice questions, but you ______ do all of them. Just choose your best 10
(a) don’t have to
(b) mustn’t
(c) don’t need
(d) aren’t
4 You ______ use a blue pen for the multiple-choice section; a regular pencil is perfectly fine.
(a) mustn’t
(b) don’t have to
(c) not have to
(d) couldn’t
5 On the other hand, you absolutely ______ use a red pen for your essay, as red ink is reserved for my grading only.
(a) don’t have to
(b) shouldn’t
(c) haven’t to
(d) mustn’t
6 Question 5 is a bonus question, meaning you ______ write an answer for it if you are running out of time.
(a) don’t have to
(b) mustn’t
(c) aren’t have to
(d) won’t
7 Please be very careful with your official answer sheets; you ______ fold them or tear the corners.
(a) don’t have to
(b) needn’t
(c) mustn’t to
(d) mustn’t
8 In Section B, there are three different essay topics provided. You ______ write about all three; just select your favorite one.
(a) haven’t to
(b) mustn’t
(c) don’t have to
(d) don’t must
9 If you finish writing your essay early, you ______ wait until the final bell rings to submit your paper.
(a) mustn’t
(b) don’t have to
(c) shouldn’t
(d) don’t have
10 But you ______ leave the examination room during the first 30 minutes. That is a strict school policy.
(a) don’t have to
(b) don’t need
(c) mustn’t
(d) mustn’t leaving
11 You are allowed to use the provided dictionary, so you ______ guess the spelling of difficult vocabulary words.
(a) mustn’t
(b) haven’t to guess
(c) don’t have to
(d) shouldn’t
12 However, you ______ use your smartphone as a dictionary. Mobile phones are completely banned during tests!
(a) don’t have to
(b) mustn’t
(c) aren’t allowed
(d) couldn’t
13 If you make a mistake on the answer sheet, you ______ ask for a new paper immediately; just use your eraser first.
(a) don’t have to
(b) mustn’t
(c) don’t must
(d) wouldn’t
14 Remember, you ______ look at the student sitting next to you. Cheating will result in an automatic zero.
(a) don’t have to
(b) mustn’t
(c) mustn’t looking
(d) needn’t
15 The final reading passage is quite long, but you ______ read every single word to find the main idea.
(a) shouldn’t
(b) mustn’t
(c) haven’t to
(d) don’t have to
16 Furthermore, you ______ write a massive introduction for your essay; a short, clear thesis statement is enough to get full marks.
(a) mustn’t
(b) don’t have to
(c) don’t need
(d) aren’t supposed
17 If you need to go to the restroom, you must raise your hand. You ______ just stand up and walk out without permission.
(a) don’t have to
(b) mustn’t
(c) mustn’t to
(d) shouldn’t
18 We will provide plenty of extra scratch paper, so you ______ write your messy draft directly on the final exam sheet.
(a) mustn’t
(b) don’t have to
(c) not have to
(d) couldn’t
19 Although the test is two hours long, you ______ stay for the entire duration if you have confidently finished and checked your work.
(a) haven’t to stay
(b) mustn’t
(c) don’t have to
(d) don’t must
20 Finally, whatever you do, you ______ forget to write your full name and student ID at the top of the page before you begin!
(a) don’t have to
(b) shouldn’t
(c) needn’t
(d) mustn’t
ANSWER KEY & EXPLANATIONS
1 (c) don’t have to
- Why it is correct: Because some questions are optional, answering all of them is not an obligation.
- Distractor Analysis: (a) “mustn’t” is a Common Mistake (implies you are forbidden from answering all questions, which is false). (b) “haven’t to” is a Structural Error. (d) “shouldn’t” is a Meaning Trap (it’s advice, not a statement of optionality).
2 (d) mustn’t
- Why it is correct: Talking during an exam is cheating. It is strictly prohibited.
- Distractor Analysis: (a) “don’t have to” is a Common Mistake. (b) “mustn’t to” is a Structural Error (modals do not take “to”). (c) “don’t must” is a Structural Error.
3 (a) don’t have to
- Why it is correct: You are given a choice (pick 10 out of 12). Doing all 12 is unnecessary.
- Distractor Analysis: (b) “mustn’t” is a Common Mistake. (c) “don’t need” is a Structural Error (requires “to” -> “don’t need to”). (d) “aren’t” is a Structural Error.
4 (b) don’t have to
- Why it is correct: Using a blue pen is optional because a pencil is also acceptable.
- Distractor Analysis: (a) “mustn’t” is a Common Mistake. (c) “not have to” is a Structural Error. (d) “couldn’t” is a Meaning Trap.
5 (d) mustn’t
- Why it is correct: Using red ink is forbidden because it is reserved for the teacher.
- Distractor Analysis: (a) “don’t have to” is a Common Mistake (implies you can use red if you want). (b) “shouldn’t” is a Meaning Trap (too weak for a strict exam rule). (c) “haven’t to” is a Structural Error.
6 (a) don’t have to
- Why it is correct: It is a bonus question, meaning writing an answer is completely optional.
- Distractor Analysis: (b) “mustn’t” is a Common Mistake. (c) “aren’t have to” is a Structural Error. (d) “won’t” is a Meaning Trap.
7 (d) mustn’t
- Why it is correct: Folding or tearing the official sheet ruins the document. It is prohibited.
- Distractor Analysis: (a) “don’t have to” is a Common Mistake. (c) “mustn’t to” is a Structural Error. (b) “needn’t” is a Meaning Trap (means “lack of necessity,” not prohibition).
8 (c) don’t have to
- Why it is correct: You only need to select one topic, removing the obligation to write about all three.
- Distractor Analysis: (b) “mustn’t” is a Common Mistake. (a) “haven’t to” is a Structural Error. (d) “don’t must” is a Structural Error.
9 (b) don’t have to
- Why it is correct: Waiting for the bell is not required if you finish early; you have the freedom to submit it.
- Distractor Analysis: (a) “mustn’t” is a Common Mistake. (d) “don’t have” is a Structural Error (missing “to”). (c) “shouldn’t” is a Meaning Trap.
10 (c) mustn’t
- Why it is correct: This is a strict school policy. Leaving in the first 30 minutes is forbidden.
- Distractor Analysis: (a) “don’t have to” is a Common Mistake. (d) “mustn’t leaving” is a Structural Error (requires bare infinitive). (b) “don’t need” is a Structural Error.
11 (c) don’t have to
- Why it is correct: Because you have a dictionary, the action of guessing is unnecessary.
- Distractor Analysis: (a) “mustn’t” is a Common Mistake. (b) “haven’t to guess” is a Structural Error. (d) “shouldn’t” is a Meaning Trap.
12 (b) mustn’t
- Why it is correct: Mobile phones are banned. Using one is strictly prohibited.
- Distractor Analysis: (a) “don’t have to” is a Common Mistake. (c) “aren’t allowed” is a Structural Error/Meaning Trap (requires “to” -> “aren’t allowed to”). (d) “couldn’t” is a Meaning Trap.
13 (a) don’t have to
- Why it is correct: You can just use an eraser, making the action of asking for a new paper unnecessary at first.
- Distractor Analysis: (b) “mustn’t” is a Common Mistake. (c) “don’t must” is a Structural Error. (d) “wouldn’t” is a Meaning Trap.
14 (b) mustn’t
- Why it is correct: Looking at another student’s paper is cheating. It is forbidden.
- Distractor Analysis: (a) “don’t have to” is a Common Mistake (if you say this, you are saying cheating is optional!). (c) “mustn’t looking” is a Structural Error. (d) “needn’t” is a Meaning Trap.
15 (d) don’t have to
- Why it is correct: Reading every single word is not an obligation; skimming is an acceptable alternative.
- Distractor Analysis: (b) “mustn’t” is a Common Mistake. (c) “haven’t to” is a Structural Error. (a) “shouldn’t” is a Meaning Trap.
16 (b) don’t have to
- Why it is correct: A massive introduction is not required for full marks. It is optional.
- Distractor Analysis: (a) “mustn’t” is a Common Mistake. (c) “don’t need” is a Structural Error (missing “to”). (d) “aren’t supposed” is a Structural Error.
17 (b) mustn’t
- Why it is correct: Walking out without permission breaks exam protocols.
- Distractor Analysis: (a) “don’t have to” is a Common Mistake. (c) “mustn’t to” is a Structural Error. (d) “shouldn’t” is a Meaning Trap.
18 (b) don’t have to
- Why it is correct: Because scratch paper is provided, drafting on the official sheet is unnecessary.
- Distractor Analysis: (a) “mustn’t” is a Common Mistake. (c) “not have to” is a Structural Error. (d) “couldn’t” is a Meaning Trap.
19 (c) don’t have to
- Why it is correct: Staying for the full two hours is not mandatory if you are already finished.
- Distractor Analysis: (b) “mustn’t” is a Common Mistake. (a) “haven’t to stay” is a Structural Error. (d) “don’t must” is a Structural Error.
20 (d) mustn’t
- Why it is correct: Forgetting your name means you get no grade. It is a critical rule not to forget.
- Distractor Analysis: (a) “don’t have to” is a Common Mistake (implies you can leave your name blank if you want). (b) “shouldn’t” is a Meaning Trap. (c) “needn’t” is a Meaning Trap.
GRAMMAR POINTS TO REMEMBER
1 DON’T HAVE TO (Optional):
- Meaning: It is NOT necessary. You have the freedom to choose. In a test, this means a question is optional, a tool is provided so you don’t need to bring your own, or an action isn’t required to pass.
- Exam Context: You don’t have to answer the bonus question. You don’t have to stay until the end if you finish early.
- Structure: Subject + don’t/doesn’t have to + Verb (bare infinitive).
2 MUSTN’T (Mandatory Rule):
- Meaning: Do NOT do this. It is against the rules. In an exam, doing this will result in a penalty, a zero, or disqualification.
- Exam Context: You mustn’t cheat. You mustn’t use your phone. You mustn’t talk to others.
- Structure: Subject + mustn’t + Verb (bare infinitive). (Never use “to”).
The Exam Tip: If doing the action gets you a zero or a penalty, use MUSTN’T. If doing the action just means you are doing extra work for no reason, use DON’T HAVE TO.