What is the author's likely purpose for including

Adam's confusion about who Cain is?

The author's likely purpose for including Adam's confusion about who Cain is, is to show that the first human beings discovered things by themselves, which is totally different to what's written in the Genesis for it doesn't include the role of God.

Explanation:

The question is related to the story entitled "Extracts from Adam's Diary" by Mark Twain. It is a comical short story published in 1893.

The story starts with Adam's narration about Eve and his reference to her as a "creature with long hair" that he seems to be annoyed of. According to Adam, the creature was always talking and it gets to name all the things.

"Cain" was being referred to as an "it" by Adam in the story because he never knew it was a human like him until later. However, Eve was so attached to it. Adam thought of it as a fish, then insect and so on. Later on, her realized it was a human being.

this would be in the imperative mood. it is a category of verb forms that are used to express orders,instructions,commands or requests.