MUST

MUST

"Must" is most commonly used to express certainty. It can also be used to express necessity or strong recommendation, although native speakers prefer the more flexible form "have to." "Must not" can be used to prohibit actions, but this sounds very severe; speakers prefer to use softer modal verbs such as "should not" or "ought not" to dissuade rather than prohibit

Affirmative

• I must go to the library.
  
  
• You must stay here until I come back.
  
  
• We must be at the airport at three o'clock.
  
  
• Everybody must wear a uniform.
  
  
• You must be joking!
  
  
• Julia must be in Paris by now.
  
  
• It must be noon already.
  
  

Negative

• You must not talk to strangers.
  
  
• We mustn't make noise.
  
  
• Mr. Williams must not smoke.
  
  

Interrogative

• Must we do everything today?
  
  
• Must you go so soon?