English Grammar : Auxiliary Verb 'Must'

Use of Auxiliary Verb 'Must' in English Grammar

Uses of Auxiliary Verb "MUST"

'Must' is modal verb most often used to express necessity and certainity, to indicate a strong intention or recommendation, to emphasize an opinion, advise or sentiment and for prohibition (when used negatively).

'Must' is stronger than should and used to show duty or obligation.

It is used in :
• Simple present tense(must)
• Present continuous tense (must be)
We use 'must' to indicate a situation which is certain or extremely likely or probable to happen or occur.
  • • He must be mad.
  • • That must be Mamta.
  • • He must be seventy five now.
  • • This must be the right address!
  • • That must have been the right restaurant.
  • • I must have left my Pen on my desk at work.
  • • He must be very tired. He's been walking all day long.
  • • This must be the place - there's a red car parked outside.
We use 'must' to indicates an action, circumstance, or situation is necessary to perform strongly.
  • • I must go now.
  • • I must stop smoking.
  • • I must get some exercise.
  • • You musn't look back - promise?
  • • We must get up early in the morning.
  • • All employees must come to staff meetings.
  • • Students must pass an entrance examination.
  • • I must send my father a card on his birthday.
  • • You must have a passport to cross the border.
  • • You must have a permit to enter the national park.
  • • People must try to be more tolerant of each other.
  • • You must listen to the teacher during the lecture.
Strong Intention:
We use 'must' to indicate something we have a very strong intention of doing in the future.
  • • I must file my tax return this weekend.
  • • I must get around to calling my sister.
  • • We must have the car checked out soon.
We use 'must' to politely introduce or emphasize an opinion or recommendation about something or someone.
  • • You must go now.
  • • You must speak politely to the customers.
  • • You must take some medicine for that cough.
  • • You must take some time off and get some rest.
Duty or Obligation:
We use 'must' to expresses moral principles, obligation or duties.
  • • We must pay taxes.
  • • We must obey what parents say.
  • • We must obey rules of the school.
  • • We must file tax returns regularly.
  • • We must stop when the traffic lights turn red.
Advise or Suggestion:
We use 'must' to make suggestions or advise to others of something positive we believe they should do.
  • • You must try this wine. It’s excellent.
  • • You must go and see the film - it's brilliant.
  • • You must come and see me next time you're in town.
  • • You must come stay with us at the river-side sometime.
  • • It was so lovely to see you. We must get together again soon!
  • • You simply must try the new Mona's Cafe on C.G.Road—it's fantastic!
When used negatively, 'must' expresses prohibition.
  • • You must not tell anyone.
  • • Policemen must not drink on duty.
  • • Students must not leave bikes here.
  • • You must not smoke in public places.
  • • Riya, you must not play in the street!
  • • Passengers must not talk to the driver.
  • • You must not drive over the speed limit.
  • • I suppose I must not touch the precious ornaments.
  • • You must not swim in that river. It's full of crocodiles.
Types of Auxiliary Verbs
(1) Auxiliary–cum–verbs.

"Auxiliary-cum-verbs" are :

These 11 auxiliaries are also used as verbs, therefore, they are called Auxiliary–cum–verbs. These are used to form Tenses. ( Please refer Tense Table).

(2) Pure Auxiliary verbs..

These 20 auxiliaries only support normal verbs, therefore, they are called Pure Auxiliary Verbs. They are also called Models or Model Auxiliary Verbs.

Related Topics :
Types of Noun in English Language
Types of Pronoun in English Language
Types of Verb in English Language
Types of Adverb in English Language
Types of Adjective in English Language
Kinds of Preposition in English Language
Types of Conjunction in English Language
Uses of Interjection words in English Language


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