Today I found myself in a situation that I asked "Which class" to a friend who said that "we are going to the class". Then one of my friends said that I should ask "what class" and another one said both (what class and which class) are correct. Who is right?
This issue I meet often when I'm talking about things, such as:
What day/ which day?
What floor / which floor?
what teacher / which teacher?
What page / which page?
What place / which place?
What line (bus) / Which line?
What /which sentence (do you agree with)?