He was sleeping/had been sleeping when...

[Tan Elaine]

He was sleeping for five hours when he heard a loud explosion.

He had been sleeping for five hours when he heard a loud explosion.

I believe both sentences are correct. Am I correct to say so?

Thanks.

[bhaisahab]

He was sleeping for five hours when he heard a loud explosion.

He had been sleeping for five hours when he heard a loud explosion.

I believe both sentences are correct. Am I correct to say so?

Thanks.

No, the second one is correct.

[rhapsomatrics]

Watch out for these words:before,after,while,during,when...they are time adverbs which agree with past perfect or past perfect progressive verbs...'He slept before I returned(incorrect) 'He had slept before I returned(correct(past perfect) ) or 'He had been sleeping before I returned'(correct(past perfect progressive) )

[rhapsomatrics]

He was sleeping for five hours when he heard a loud explosion.

He had been sleeping for five hours when he heard a loud explosion.

I believe both sentences are correct. Am I correct to say so?

Thanks.

You can also say 'he had slept for five hours..."

[5jj]

Watch out for these words:space"before",space"after",space"while",space"during",space"when"...they are time adverbs which agree are used (?) with past perfect or past perfect progressive verbs.

These words can be used with many tenses and aspects English. Here are some examples with past tense forms:

He changed before he left.
He left after I arrived.
She washed up while I was finishing my reports.
George looked unhappy when I told him the news.

In the original sentence, when is a conjunction.
During is a preposition.
.