Hughes wrote “Mother to Son” in free verse, which means the poem doesn’t follow a strict meter. Instead, the lines vary widely in length, ranging from one to ten syllables. This lack of metrical restriction allows Hughes to focus on the shifting cadences of the speaker’s voice. The speaker of the poem is a Black woman who’s addressing her son, at once recounting the challenges she’s faced in her life and encouraging him to persist through the challenges in his own. Hughes uses the varying length and rhythm of each line to shape the rhetorical effects of the speaker’s address. As an example, consider the seven lines that open the poem. Let’s begin with just the first two:

     Well, son, I’ll tell you:
     Life for me ain’t been no crystal stair.

These lines emphasize the significant obstacles that have stood in the speaker’s way throughout her life. The speaker rhetorically prepares her son for the weight of what she’s about to say in the first line, where the heavy pauses after “well” and “son” establish a serious tone. The punctuated rhythm in this line then yields to another line that contains twice as many syllables but flows much more freely, allowing the speaker to declare the thesis of her address as plainly as possible.

After preparing her son for her speech and introducing its main theme, the speaker then goes on to make a list (lines 3–5):

     It’s had tacks in it,
     And splinters,
     And boards torn up,

Each of these lines is short, but they are also slightly staggered in length: five syllables, then three, then four. This staggering helps build a sense of tension as the speaker itemizes the numerous obstacles she’s faced. The tension continues to build in the following line, and then releases in the next:

     And places with no carpet on the floor—
     Bare.

The first line quoted here is one of the longest in the entire poem, and its length makes sense in context, given that it marks the culmination of the speaker’s list. In the next line, Hughes goes hard in the opposite direction, following the poem’s longest line with the poem’s shortest one: “Bare.” With this single word, the speaker at once summarizes the previous line and gives it an added emphasis that decisively punctuates the entire five-line sentence. By manipulating line length in this way, Hughes carefully shapes the rhetorical effects of the speaker’s address.