Difference Between Must and Have To (With Table)

We come across many situations where there would be an obligation or necessity to perform a particular task. ‘Must’ and ‘Have to’ are the words often used in English to express necessity, obligation or responsibility. These words are used when the speaker wishes to express a necessity or a compulsion in executing a particular task. For Example, Soldiers have to finish this operation at the end of the day. Though both terms are used in synonymous with each other for obligation, there exists a minor difference between the two words.

The term ‘must’ is a modal verb which implies that the task ought to be done. It emphasizes a duty or necessity that needs to be done at the present. Consider the following statement – I must finish the work within an hour. This statement means that the subject must execute the task, putting the entire onus on the subject. It is a duty bestowed upon the subject which has to be done at present. Whereas the term ‘have to’ is a semi modal verb which also implies a necessity but in a different way. When the term ‘have to’ is used, it means that the task done would have been imposed on the doer by someone.

For example, consider the following statement. You have to finish the task this week. This statement emphasizes that the subject has the necessity to complete the work. But the work has been imposed by another person.

Must vs Have To

The difference between ‘must’ and ‘have to’ is that the term ‘must’ indicate an obligation that has to be done at the present. While the term ‘have to’ is used to indicate a necessity or duty to be done in past or present or future. It is because of this flexibility in the usage, the term ‘have to’ is commonly used.

Comparison Table Between Must and Have To

Parameters of ComparisonMustHave To
MeaningUsed to express an obligation or duty that has to be done by the doer.Denotes a duty done by the doer which is imposed directly or indirectly upon on the doer by someone else.
TenseUsed to denote activities to be done at present.Used to denote duty or necessity to be done at the past, present or future.
FunctionIt stresses the duty that is necessary and important for the speaker.It signifies that the duty done by the subject is imposed directly or indirectly by somebody.
VerbIt acts as a modal verb.It acts as a semi-modal verb.
PronounCan be formed without the help of an auxiliary verb.Cannot be formed without the help of an auxiliary verb.
ExampleI must travel to Chennai tomorrow.The workers have to finish this work on time.

What is Must?

The term ‘must’ is a modal verb which denotes a necessity or duty that must be fulfilled by the subject or the doer at the present. It is used when some work has to be done by the subject at the moment. The subject has the moral responsibility to carry out the given task. Consider the following statements

  1. I must finish the work by the end of the day.
  2. I must not move when the traffic light shows red.

In the above statements, the subject is morally obliged to do the work or the duty. It is an absolute necessity and not imposed by others. The subject does the work for his or her benefit and failing to do will affect the subject the most. To deliver a negative sentence, ‘not’ is added before the modal verb which emphasises strong prohibition on the work mentioned in the statement. For Example, He must not drive the car. It implies that the subject is not allowed to do the work (obligation).  The term ‘must’ is used to convey a stronger meaning in the statement. Must is also used to indicate the logic or probability of an event.

What is Have To?

The term ‘Have to’ is a semi-modal verb which is also used to denote an obligation or a work that must be done. But the task might be imposed on the subject by somebody. The subject is fulfilling the necessity of someone else. Consider the following statements.

  1. I have to buy those books for my brother.
  2. I have to finish this work for my boss.

These statements imply a work to be done by the subject imposed by someone else. Have to can be used in all three tenses (Past, Present and Future). It is also used to denote general rules or obligations that must be followed. Similar to ‘must’, the addition of not alone is required for a negative statement. But it does not enforce the prohibition of work on the subject. Consider a statement.

  • You don’t have to do this.

In this statement, the subject is informed that he/she doesn’t need to do the work. But this does not prevent the subject from doing the work as no obligation was made to the subject. The subject may or may not do the task which cannot be forced.

Main Differences Between Must and Have To

  1. The term ‘must’ is used to express about obligation, work or duty to be done at the present. ‘Have to’ is used to denote the obligation in all the tenses.
  2. ‘Must’ is used to denote a duty in which the subject has moral responsibility and necessity in doing it. ‘Have to’ is used to denote a duty, necessity or obligation imposed on the subject by others.
  3. ‘Must’ acts as a modal verb while ‘Have To’ acts as a semi-modal verb.
  4. ‘Must’ is used for internal and personal obligation while ‘Have to’ is used for the external obligation.
  5. While negative statements using ‘must’ may not require an auxiliary verb for framing the sentence, the auxiliary verb is a must for negative ‘have to’ statements.

Conclusion

Though ‘Have to’ and ‘Must’ is used for mentioning obligations, they have a clear difference in their usage. The word ‘must’ can be used for denoting events at the moment (present) whereas ‘Have to’ can be used for all the tenses (present, past and future). Must is used for personal obligations while ‘Have to’ is used for external responsibility or commitment.

References

  1. https://www.merriam-webster.com/dictionary/must
  2. https://www.merriam-webster.com/dictionary/have%20to
x
2D vs 3D