• What vs Which in Questions

• 
• Use what and which to ask information questions. 

  
  

  Use which when the range of answers is limited or restricted. 

  -Which Harry Potter book do you like?  

  (The options are limited to the Harry Potter books.) 

  
  

  Use what with general questions without limits or restrictions.

  -What is your favorite book? 

  (The options are limitless and include every book.) 
•  Click on the play button to hear the audio

• Which	What
  Which computer is more expensive?  (Limited to the computers available)	What computer is more expensive? (General question with no limits)
  Which is the capital of Spain, Madrid or Barcelona? (Restricted to two choices)	What is the capital of Spain? (General question with no restrictions)

 

Source : Alison