What You Must Know About ‘Must’ and ‘Have to’ in English

by | Jul 8, 2025 | Career Development

Mastering the usage of must and have to is crucial for conveying obligation in English. Both expressions are used to indicate that something is necessary or required, but their usage can differ in various contexts.

Grammatical Differences Between “Must” and “Have to”

While both must and have to express obligation, they do have some differences. “Must” is a modal verb, and it doesn’t change form to match the subject. Conversely, “have to” is not a modal verb, so it can change based on the subject and tense. For instance, it becomes “has to” in the third-person singular.

What's your English level?

Discover your level now: A1/A2/B1/B2/C1/C2 and GET your certificate!

Examples:

Subject Must (Present) Have to (Present)
I/You/We/They must go have to go
He/She/It must go has to go

Nuances in Meaning

The choice between must and have to can also convey different nuances. “Must” is often used for personal obligations or internal necessity, suggesting a stronger or more formal obligation. On the other hand, “have to” implies external obligations, such as rules or laws from an outside authority.

Examples:

  • “I must study for the test.” (personal obligation)
  • “I have to wear a uniform at school.” (external requirement)

Usage in Past and Future Tense

Although “must” is limited to present and future contexts, “have to” can be modified to reflect both past and future tenses. This makes “have to” more versatile in various situations.

Example Sentences:

  • “I had to leave early yesterday.” (Past obligation)
  • “I will have to finish my report by tomorrow.” (Future obligation)

Formality and Social Contexts

“Must” is typically more formal than “have to”. In informal conversation, “have to” is preferred. Understanding this social nuance can help learners use these terms appropriately in different settings.

Practice and Check Your Understanding

To test your understanding and ensure you use these terms correctly, consider real-life situations where these expressions apply. You can check your English level using the GET Global English Test.

Conclusion

In English, correctly using “must” and “have to” is important for expressing obligation. Remember that while both can often be used interchangeably, the context, formality, and underlying implications guide correct usage. For deeper exploration, resources like Cambridge Dictionary and the Merriam-Webster can provide further examples and practice exercises.

Importance of Understanding Modal Verbs

Modal verbs play a vital role in English grammar, expressing various degrees of necessity, possibility, permission, and ability. Understanding the nuances and differences between modal verbs can greatly enhance your language proficiency.

Statistics on Modal Verb Usage

Research shows that modal verbs like “must” and “have to” are among the most commonly used in daily conversations and written texts. Mastering their usage can significantly improve your communication skills.

Case Study: Real-Life Application

Consider a scenario where the correct use of “must” and “have to” determined the outcome. In a legal context, misinterpreting these obligations could lead to serious consequences. This highlights the importance of precise language use.

Q&A: Common Queries About Modal Verbs

Q: Can “must” and “have to” always be used interchangeably?
A: While they share similarities, the subtle differences in meaning and formality make certain contexts more suitable for one over the other.

Q: Are modal verbs like these the same in all languages?
A: Not necessarily. Different languages may have unique ways of expressing obligation and necessity, so it’s essential to grasp these distinctions when learning a new language.

Interactive Learning Activities

Engage in interactive quizzes and exercises to practice using “must” and “have to” correctly. Active participation in language activities can reinforce your understanding and retention of grammar concepts.

Test your English level and get your certificate!

Find out your English level

Takes only ~20 minutes 🎉