1a. While sitting in the sun, the old man fell asleep.
1b. While sitting in the sun, the old man had fallen asleep.
2a. He made several beautiful kites.
2b. He had made several beautiful kites.
3a. We anticipated this happening.
3b. We had anticipated this happening.
4a. You would have been successful if you listened to my advice.
4b. You would have been successful if you had listened to my advice.
Please correct the above sentences with correct tenses.
Thanks.
They’re correct as standalone sentences. Once placed within a specific context the correct tense to use would be dictated by the wider meaning and they would not be interchangeable.