Which of the following sentences is correct?
Why have you done this?
Correct
Why you had done this?
Why you have done this?
Why did you done this?
Explanation:
Correct Answer is: Why have you done this?
Sentence টি প্রশ্নবোধক না হলে হতো `You have done this`। এসব sentence কে why দ্বারা interrogative করতে হলে নিচের sentence অনুযায়ী করতে হবে। Why + auxiliary verb + subject + principle verb + objective or others. সুতরাং why have you done this sentence টি সঠিক।