Question

You ____ (sleep) for three hours now. Correct the tense.​

Answer 1

You had slept for three hours.

I guess this answer would be correct friend if not then you can report this answer.

Answer 2

You have been sleeping for three hours now.

• We were supposed to fill in the given blank with the help of the correct form of the given verb.
• On observing the sentence, we can say that the sentence must be in the present perfect tense.
• The usual form of writing present perfect tense is: has/have been + verb-ing.
• The present perfect tense is used when we want to show that the action started in the past and is going on in the present too.