Difference Between Shall and Must (With Table)

‘Shall’ and ‘Must’ are two different words in the English language with similar meanings in the English dictionary. Both of these words mean that something is ought to be or be mandatory to be carried out as a duty. Although both have similar meanings, sometimes they cannot be used in place of each other.

Shall vs Must

The difference between ”shall’ and ”must” is that as a verb, ‘shall’ is a modal auxiliary verb, whereas ‘must’ is something to do with certainty, indicating that the person is confident that the topic will have executed the predicated.

The word ‘shall’ is usually noted to be used when a sentence wishes to carry something, which would take place in the future. It’s the replacement to the word will. This word is usually used to ask to offer something or ask for a piece of information or advice. This word is also used to indicate that something has to happen.

The word ‘must’ emphasizes a sentence that wishes to convey something to be for sure or mandatory done at a specific time. This term is used to denote that the action has to take place for sure. ‘Must’ is the most basic and straightforward of saying that something is compulsory or mandatory. It means that you have no choice whether to do or not to do something. It can only be used in the present form to describe an obligation or future form for a future commitment.

Comparison Table Between Shall and Must

Parameters Of ComparisonShallMust
Derivation Of The WordFound in old English form. It was used correctly from the 17th century and later became a replacement for the word ‘will.’Found in old English and was used correctly right before the 12th century.
Grammatical FormThis word is a modal verb used in the place of the first, second, and third-person pronoun. It subjects a sentence leading to future tense.This word is a modal auxiliary verb. Affirmative+form. It must come first in a verb phrase (after the subject and before the second verb).
PurposeGenerally, this word is used to express ideas and rules and when a speaker wishes to convey something that will take place in the future.This word is generally used to emphasize the need for a particular requirement in a sentence that has to be done. Sometimes used in past tense too.
Example”You shall go to the ball with this man.””I must buy some new slippers.”
Tense and Writing FormatIt expresses future tense.
Usually used in Formal communication.
It can express present as well as past tense.
Mostly used in informal communication.

What is Shall?

The word ‘shall’ is actually a modal auxiliary verb that indicates a strong assertion, desire, or intention to do something. Whenever this word is put in a sentence, it always refers to take place in the near future. This word is sometimes used to give an order or a to while making a promise to someone. It also indicates the prerequisite of something or an event.

‘Shall’ appears in a sentence as a first-person pronoun having a traditional approach to suggest an opinion in the future tense. Example—
1. ”I shall try my best to attend my cousin’s wedding this weekend.”
2. ”I shall study hard during the Diwali vacations and score good marks in my examinations.”

When shall is used as a second or third person, it is denoted for opinion, signifying the phrase or sentence’s intensity. Example—
1. ”The students shall attend the online zoom meet, no matter how sick or busy they might be!”
2. ”You shall deliver the speech with utmost confidence and passion!”

The word shall is most commonly used to express laws stated by a form or entity. Example —
1. ”The government of our country shall make great strides in technology development in the upcoming years to bring about production efficiency, leading to rising in the economy of our country.”
2. ”The board of directors shall collectively decide who would be the upcoming CEO of the company.”

What is Must?

The word ‘Must’ is an English word that indicates the particularity or need for a specific something. Usually, when a sentence has to mean something are not to be overlooked or missed, it must be used as a noun. By using logic, ‘must’ help in making a conclusion or end statement.
This word is generally used with a past participle very, which means past possibilities. Example—
1. ”She must have found the keys.”
2. ”They must have reached home.”

The word ‘must’ is also used to give a recommendation emphatically. Example—
1. ”You must make one of these smoothie- makers, they’re great!”
2. ”You must see this movie. It is brilliant!”

Must is sometimes used to speculate the truth of something. Example—
1. ”She must be mad!”
2. ”There must be some mistake.”
3. ”You must be joking!”

‘Must’ can also be used in an interrogative sentence. Example —
1. ”Must you go soon?”
2. ”Must you go with them for a movie?”

‘Must’ is often used even with a negative statement to forbid someone’s to do something. Example—
1. ”You must not cross when the light is red.”
2. ”You must not say things which would offend people.”

Main Differences Between Shall and Must

  1. Shall refers to absolute requirement, whereas must is equivalent to mere requirement.
  2. Shall is rare in everyday conversation, whereas must is used in everyday conversation.
  3. Shall is used in future tense whereas must maybe be used in the present and past tense.
  4. Shall is an option to do something, but ‘must’ doesn’t have an option as such whether to do or not to do something.
  5. ‘Shall’ signifies weightlessness and looks pretentious, while ‘must’ signifies and looks natural whole speaking.


The verb must is generally used to express the certainty of a sentence. In contrast, the verb is frequently used to express obligation and duty, usually for legal terms (formal communication). Must be used for requiring whereas shall is equivocal and rarely occurs in an everyday. Must is used informally. ‘Shall’ signifies only in future test and must in both the present as well as future. Both the words shall and must have similar meanings but are to be used in a sentence in a very different context, or else the meaning of the sentence would entirely change, leading to miscommunication.


  1. https://heinonline.org/hol-cgi-bin/get_pdf.cgi?handle=hein.journals/aklr43&section=38
  2. https://www.frontiersin.org/articles/10.3389/fnint.2012.00123/full