Question

What is the effect of the unusual syntax in these lines from "The Negro Speaks of Rivers" by Langston Hughes?

Answer 1

I've known rivers:
I've known rivers ancient as the world and older than the flow of human blood in
human veins.

Answer 2

It models the flowing sensation of a river

It focuses attention on the overall subject.

It helps to maintain a static feeling throughout the stanza.

It helps maintain a steady pace from line to line.