Question

Change in Imperative sentence
I had slept
I was sleeping
I had been sleeping
I slept

change in Interrogative sentence
I had slept
I was sleeping
I had been sleeping
I slept
Change in Exclamatory sentence
I had slept
I was sleeping
I had been sleeping
I slept​

Answer 1

Explanation:

Sorry, don't know imperative.

Interrogative Sentences

1 Had I slept?

2 Was I sleeping?

3 Did I sleep?