Know Your English (Aug 2001)

Know your English

Is it OK to say, "Which class are you studying?"

This seems to be a common way of asking the question in our country. Most people accept it the way it is - at least in speech. If you wish to be grammatically correct the word "in" is required. You could either say, "In which class are you studying?" or "Which class are you studying in?" It is also possible to ask a person, "Which class are you in?" Here are a few more examples.
* In which room did the murder take place?
* Which room did the murder take place in?


Source:
The Hindu daily, Tuesday, August 07, 2001