sentence structure

[Unregistered]

dear sir/ madam,
i need to know the correct syntax of the following interrogative sentence:

which school do you read into?

which school do you read?

in which school do you read?

as per my knowledge of the subject the first one is correct while my senior advocates for the second one. please help me to choose the right one.

rays sparkle

[tigerpaws]

As for syntax, I would vote for #3. However, in order to make sense I would change the word "read" to study or attend. Then the sentences would be:
1. Which school do you attend?
2. the same
3. In which school do you study?
Perhaps I have misunderstood your question. I hope this helps.