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Must, Have to, Need to, and Don't Have to: correct answers

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Must, Have to, Need to, and Don't Have to

When something is absolutely required, do you say "You must wear a uniform" or "You have to wear a uniform"? Both are correct — but what about when something is not necessary? Saying "You don't have to wake up early" means it's your choice, while "You mustn't wake up early" means it's forbidden. Mixing these up can completely change your meaning!

This challenge tests your ability to choose the right modal of necessity across real-life scenarios: school rules (uniforms, student IDs, arrival times), doctor's instructions (taking medicine, dietary advice), travel requirements (passports, check-in procedures, packing checklists), workplace dress codes, flatmate chores (bills, bins, bathroom cleaning), and gym membership rules. You'll practise distinguishing between must and have to for obligation, need to for necessity, and don't have to for things that are optional — not forbidden.

Work through 15 questions in four formats — single-choice, multi-choice, drop-down, and drag-and-drop — so you'll identify correct usage, spot common errors, and complete conversations in context.

Try the quiz to check your knowledge!

MediumA2 | Elementary | Pre-intermediateA2Auxiliary verbInfinitiveModal verbNegationVerb

Correct answers

Question 1

Lina is preparing for her first international flight. ✈️ Select ALL the options that could correctly complete the sentence below.
"Passengers ___ show a valid passport at the check-in counter."

The correct answers are must, have to, and need to.

Showing a passport at check-in is an obligation, so we need a modal that expresses necessity. Must, have to, and need to can all express that something is required. "Don't have to" means it is not necessary (the opposite meaning), and "mustn't" means it is prohibited — neither fits the context of a requirement.

Question 2

Choose the correct phrase to complete the sentence.

It's Saturday — no school today! You ___ wake up early. You can sleep in! 🎉

The correct answer is don't have to.

"Don't have to" means there is no obligation — it is not necessary. Since there is no school on Saturday, waking up early is not required (but you still can if you want to!).

Question 3

Marco just visited the doctor and is telling his friend what the doctor said. Select ALL the sentences where a modal of necessity is used correctly.

The correct answers are The doctor said I have to take this medicine twice a day, I must stop eating so much sugar, and I don't have to stay in bed — just rest a little.

"Have to not forget" is incorrect — you cannot place "not" between "have to" and the verb. The correct form is "I must not forget my next appointment" or "I mustn't forget." Be careful: "I don't have to forget" would mean "forgetting is not required" — a completely different (and strange) meaning! "Need take" is missing "to" — the correct form is "need to take." Remember: need to always requires "to" before the base verb.

Question 4

Help the traveler complete her checklist before flying abroad. Choose the correct word for each gap! ✈️

"OK, let me think… I need to renew my passport because it expires next week. I don't have to buy a travel adapter since the hotel provides them for free. And the airline website says passengers must check in online at least 24 hours before departure."

The correct answer for the first blank is need to.

Need to expresses a personal necessity — her passport is expiring, so renewing it is essential. ("Must to" is never grammatically correct.)

The correct answer for the second blank is don't have to.

Don't have to means it is not necessary — the hotel already provides adapters, so buying one is optional.

The correct answer for the third blank is must.

Must is used for a strong obligation set by the airline. Note: "needs to" would require the subject "he/she" — with "passengers" (plural), it would be "need to," making "needs to" grammatically wrong here.

Question 5

Choose the correct phrase to complete the sentence.

My friend is flying to another country next week. She ___ get a passport before the trip, or they won't let her on the plane! ✈️

The correct answer is needs to.

"Needs to" expresses necessity — something that is required. A passport is essential for international travel, so without one she cannot fly. "Doesn't have to" would mean a passport is optional, which is incorrect here.

Question 6

It's Saturday morning and you have zero responsibilities — hooray! 🎉 Select ALL the sentences that correctly express that something is NOT necessary.

The correct answers are I don't have to wake up early today, We don't need to go to school on Saturdays, and You don't have to cook — we can order pizza!.

"Mustn't" does NOT mean "not necessary" — it means "prohibited" (you are not allowed to). "Doesn't has to" is grammatically incorrect; the correct form is "doesn't have to." Use don't have to or don't need to when something is not required.

Question 7

It's the first day at a new school! Help the student understand the rules by choosing the correct option for each blank.
All students _________________________ wear a uniform — it's the school's rule. However, you _________________________ bring your own laptop because the school provides one for every student. You _________________________ use your phone during lessons — teachers will confiscate it immediately.

The correct answers are have to, don't have to, and must not.

We use have to for external rules and obligations — the school requires uniforms. Don't have to means something is NOT necessary — bringing a laptop is optional because the school provides one. Must not expresses prohibition — using your phone is forbidden, and there is a consequence if you do.

Question 8

Choose the correct word to complete the doctor's instruction.

"Your cough is getting worse. You ___ take this medicine three times a day — it's very important."

The correct answer is must.

"Must" expresses strong necessity or obligation. The doctor is telling the patient it is essential to take the medicine. "Don't have to" would mean it's optional, which contradicts the doctor's serious advice.

Question 9

Two flatmates are dividing up household duties. Complete their conversation by selecting the correct option for each blank.
Alex: "We _________________________ pay the electricity bill by Friday, or they'll cut our power!"
Sam: "Got it. What about the dishes?"
Alex: "Well, you _________________________ wash them tonight — I already did them. But you _________________________ take out the rubbish because it's starting to smell."

The correct answers are must, don't have to, and need to.

Must expresses strong necessity — there's a deadline and a serious consequence. Don't have to means it's not necessary because the task is already done. Need to shows that taking out the rubbish is necessary due to the situation (the smell!).

Question 10

Help complete this school announcement by choosing the correct word for each blank. 🏫

"Attention, students! You have to wear your uniform every day — it's a school rule, not a choice. However, you don't have to bring lunch from home because the cafeteria is open. Also, be careful with grammar: you should never write 'must to' because must is never followed by 'to'."

The correct answer for the first blank is have to.

We use have to for external rules and obligations imposed by others. Should is too weak for a strict school rule, and don't have to would mean the uniform is optional — but the sentence says "it's a school rule, not a choice."

The correct answer for the second blank is don't have to.

Don't have to means something is NOT necessary — bringing lunch is optional because the cafeteria is available. Have to would mean it's required, and should doesn't fit the meaning of the sentence.

The correct answer for the third blank is never followed by 'to'.

Must is NEVER followed by "to." We say "must go," not "must to go." This is a common learner error worth remembering!

Question 11

Choose the sentence that correctly uses a modal of necessity.

Tom just started a new job at a restaurant. The manager told him about the dress code.

The correct answer is "You have to wear the uniform — it's required every day."

"Have to" expresses an external obligation or rule. Since the uniform is required, "have to" fits perfectly. The other options contradict the second part of the sentence: "don't have to" and "don't need to" mean it's optional, and "must not" means it is forbidden — the opposite of what's intended!

Question 12

Your new flatmate left you a note on the fridge. Choose the correct words to complete it! 🧹

"Hey! A few things about the flat: We have to take the bins out every Thursday — the council collects them Friday morning. You don't have to clean the bathroom today because I already did it this morning. Oh, and the landlord said we must keep the front door locked at all times. Safety first! 🔑"

The correct answer for the first blank is have to.

Have to is used for an external obligation — the council sets the collection schedule. Note: "must to" is never correct.

The correct answer for the second blank is don't have to.

Don't have to means there is no necessity — the bathroom is already clean, so it's not needed.

The correct answer for the third blank is must.

Must is used here because the landlord is giving a strong, direct instruction about safety. Both "must" and "have to" can express obligation, but "must" often reflects the speaker's/authority's strong personal insistence.

Question 13

A travel blogger is sharing tips with first-time visitors to Japan. Help complete the advice by selecting the correct option for each blank.
"If you're visiting Japan, you _________________________ try the street food — it's absolutely incredible! You _________________________ speak Japanese, though, because many people understand some English. But you _________________________ eat on the train — it's considered very rude, and other passengers will be uncomfortable."

The correct answers are must, don't have to, and must not.

Must is used here for a strong personal recommendation — the blogger feels very strongly about it. Don't have to means speaking Japanese is not necessary — you can manage without it. Must not expresses prohibition — eating on the train is not allowed because it is considered rude. Notice the important difference: don't have to = it's not necessary (you have a choice), while must not = it's prohibited (don't do it!).

Question 14

It's the first day at a new school, and you're reading the student handbook. Select ALL the sentences that correctly express necessity or obligation.

The correct answers are Students must wear a uniform every day, You need to bring your student ID to every exam, and You have to return library books within two weeks.

"Don't have to" means something is NOT necessary, so it contradicts "it's required." Also, "must" is never followed by "to" — we say "must check," not "must to check." The three correct options all properly express obligation using must, need to, and have to.

Question 15

A gym receptionist is explaining the membership rules to a new member. Choose the correct option for each blank.
"Welcome! You _________________________ show your membership card every time you enter the gym — it's our security policy. You _________________________ bring your own towel because we provide fresh ones for free. One more thing: you _________________________ use your phone in the weight room. It distracts other members and could cause accidents!"

The correct answers are have to, don't have to, and must not.

Have to expresses an external obligation — the gym requires you to show your card. Don't have to means bringing a towel is not necessary because the gym provides them. Must not expresses a prohibition — using your phone in the weight room is forbidden because it is dangerous and distracting. Note the key difference: don't have to means "it's not necessary," while must not means "it is not allowed."

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