Difference between Should and Must

Should and Must: Have you ever gotten confused while using the terms “should” and “must”? Both of them are modal auxiliary verbs in English, where modal verbs are used to express ability, necessity, conditionality, possibility, and permission. “Should” is used to express conditionality, whereas “must” is used to express a strong obligation. In this article, we learn about the difference between “should” and “must.”

Should vs Must

Meaning of Should

The word “should” is the past form of the verb “shall.” It is also a modal verb and has different meanings that vary with the context of the sentence. It is often used to express conditionality, advice, obligation, duty, or correctness, and is also used to express wishes or desires.

Usage of Should

• It is used to give advice. For example, maybe you should have attempted that exam once. 
• It is used to indicate obligation, duty, or correctness. For example, we should finish this work by tomorrow.
• It is used to indicate the probability or possibility of a situation. For example, Hema should have finished cooking by now.

Examples

• What should I tell them now?
• You should leave now; it’s already late.
• I shouldn’t have come here, leaving her alone.
• You should have told her about your feelings.

Meaning of Must

The word “must” is a modal verb that is used to express a stronger obligation, necessity, or certainty. It is also used when we speak about rules or laws. It is mostly used for expressing a stronger point of view.

Usage of Must

• It is used to express an obligation. For example, we must study for our upcoming final exams.
• It is used to express necessity. For example, you must have a minimum pass percentage of 50 percent to be eligible for this job. 
• It is also used to express certainty. For example, she must be very tired of all the happenings around her.
• It is used when we speak about rules or laws. For example, everyone must follow the traffic rules.

Examples

• We must not leave the entire work to her.
• You must try this dress; it looks good on you.
• You must wear your seat belt while you are driving a car.
• He must reach the examination hall fifteen minutes before the exam.

Should	Must
It is used to give advice.  It is used to indicate the probability of a situation.  It is used to express desires or wishes.	It is used to express obligation. It is used to express necessity.  It is also used to express certainty.
It has a lower degree of emphasis.	It has a high degree of emphasis.
It is less formal compared to “must.”	It is more formal compared to “should.”
Examples: They should have stayed for a little longer. I shouldn’t have listened to her words blindly.	Examples: We must submit our assignment by Friday. You must call your parents and inform them about the results.

Conclusion

In this article, we have discussed the differences between “should” and “must,” as well as their meaning and usage, with examples. Though “should” and “must” have similar meanings, there are slight differences between them. Remember that “must” has a high degree of emphasis, whereas “should” has a lower degree of emphasis.