Hughes wrote “The Negro Speaks of Rivers” in free verse, which means the poem doesn’t have a regular meter. Setting aside more traditional ideas about maintaining regular rhythm, Hughes opted for a more flexible approach. This approach allowed him to vary not just the metrical patterning of each line, but also the lengths of each line. As a representative example, consider the poem’s first three lines:

I’ve known / ri-vers:
I’ve known / ri-vers / an-cient / as the / world and / ol-der / than the / flow of / hu-man /
blood in / hu-man / veins.

My soul / has grown deep / like the / ri-vers.

The first and most obvious feature of this passage is the varied line lengths. Whereas the first line has four syllables and the last line has nine, the middle line has a whopping 23. Also significant is the way each line has its own characteristic rhythm. Note how the first line contains mostly stressed syllables, which perhaps evokes the slow and steady pooling of water. This pooling is then followed by a rushing flow in the second line, most of which has a rapid DUM-da rhythm composed of metrical feet known as trochees (stressed–unstressed). The rhythm slows again in the third line, but this time it’s more varied, possibly suggesting the swirling motion of water as it eddies after passing through some rapids. Hughes achieves similar effects at other places in the poem, creating an overall impression of a river wending its way through a landscape, its flow speeding up and slowing down with the shifts in the terrain.