What is the purpose of a literary analysis essay?

Asap that time of year thou mayst in me behold when yellow leaves, or none, or few do hang upon those boughs which shake against the cold, bare ruined choirs, where late the sweet birds sang. in this excerpt, what is the best meaning for the word "late"? not on time until recently dead well into the evening

If one writes logically, he will prove his point. is this sentence correct or contains an unwarranted shift in person?

What is the message? how does langston hughes convey the message in this poem?