Must In Questions And Negatives

Must can be used in questions to ask about what the hearer thinks is necessary.

  • Must I clean all the windows? (= Do you think that I should clean all the windows?)
  • Must we wait for his approval? (= Do you think that we should wait for his approval?)
  • Must we buy a new car? (= Do you think that we should buy a new car?)

It is also possible to express these ideas with have to.

  • Do I have to clean all the windows?
  • Do we have to wait for his approval?
  • Do we have to buy a new car?

Negatives

Must not / mustn’t is used to prohibit – to say that things must not be done.

  • You must not take this medicine without a prescription.
  • She must not reveal this secret to anybody.
  • He must not leave the country without obtaining the necessary permission.
  • She must not discontinue her studies.

Note that must not / mustn’t is used to prohibit. It is not used to say that things are unnecessary. That idea is expressed with do not need to or do not have to.

  • You don’t need to get a visa to go to Nepal. (NOT You must not get a visa to go to Nepal.)

Compare:

  • You don’t have to work on Sundays. (= You have no obligation to work on Sundays – it is not necessary.)
  • You must not work on Sundays. (= You are prohibited from working on Sundays.)
  • You don’t have to wait. (= It is not necessary for you to wait.)
  • You must not wait. (= You are prohibited from waiting.)
image_pdfimage_print

Manjusha Nambiar

Hi, I am Manjusha. This is my blog where I give English grammar lessons and worksheets.

Leave a Reply

Your email address will not be published. Required fields are marked *