• Other Uses of Must and Have to

• 
• Must and have to usually describe an obligation,  but they have other uses.  

  You can also use must and have to for:

  1. deductions (an opinion based on facts)

  2. conclusions (an opinion based on thoughts)

  
  

  The form for these two uses is the same.
  

  
  

  modal + base verb

  -He must be late for a meeting.

  -He has to* be late for a meeting.

  -He's got to be late for a meeting.

  
  

  *Remember! Match have to or has to with the subject.
•  Click on the play button to hear the audio

• John must be allergic to peanuts.	They must be stuck in traffic.
  Sara has to be hungry.	You've got to be joking!

 

Source : Alison