Modal Verbs of Obligation (must, have to, should) grammar Exercise

Practise choosing “must”, “have to”, or “should” to express obligation, necessity, and recommendations in real-life contexts.

Exercise Guide

How to complete:

Read each paragraph and select the modal verb that best expresses the level of obligation. Think about whether the sentence describes a strong rule, a necessity, or friendly advice.

  • Use “must” for strong internal or official obligations.
  • Use “have to” for external requirements or unavoidable duties.
  • Use “should” for recommendations, suggestions, or mild obligations.

Success tips:

  • Check who imposes the obligation—yourself, an authority, or social expectations.
  • “Must” often sounds stronger and more urgent than “have to”.
  • “Should” is softer and fits advice, best practices, or gentle reminders.
  • Identify time expressions; past obligations often use “had to”.

Knowledge:

English speakers juggle several modal verbs to describe obligation. Recognising the difference between personal duty, external rules, and helpful advice will help your sentences sound precise and natural.

These exercises cover workplace policies, school expectations, and everyday responsibilities, so you can switch comfortably among “must”, “have to”, and “should”.

Complete the Exercise

Paragraph 1

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Employees wear ID badges at all times, they sign in before meetings, and they greet visitors courteously.
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Paragraph 2

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Students submit the assignment by Friday, but if they are ill they email the instructor, and they review the rubric beforehand.
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Paragraph 3

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You wear a helmet on the construction site, contractors follow the safety checklist, and visitors stay behind the barriers.
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Paragraph 4

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Every morning, I take my medication, my doctor says I schedule a follow-up, and I avoid certain foods for now.
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Paragraph 5

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We arrive at the airport two hours early, since the airline check passports carefully, and we pack light to save time.
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Paragraph 6

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Team leaders submit feedback by Monday, analysts attend the briefing, and interns ask questions if they are unsure.
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Paragraph 7

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During storms, drivers turn on their headlights, buses adjust schedules, and pedestrians seek shelter promptly.
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Paragraph 8

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Guests RSVP by the tenth, caterers receive final numbers, and hosts prepare a few extra seats.
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Paragraph 9

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If you feel unwell, you inform your supervisor immediately, you see the nurse, and you rest at home afterward.
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Paragraph 10

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Before launch, engineers run diagnostic tests, designers update the assets, and marketers coordinate the announcement.
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Paragraph 11

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Parents sign the permission slips, students bring their lunches, and chaperones review the safety rules.
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Paragraph 12

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Remote workers secure their Wi-Fi networks, they follow company password policies, and they log off at the end of each day.
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Paragraph 13

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Volunteers arrive by 8 AM, they wear closed-toe shoes, and they bring reusable water bottles.
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Paragraph 14

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Borrowers return tools clean, they report any damage, and they donate supplies if possible.
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Paragraph 15

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We finish this report today, we call the client before six, and we schedule a follow-up meeting for next week.
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