“Theme for English B” uses both end-stop and enjambment throughout the poem. However, the speaker doesn’t establish a pattern or a set of rules about when he uses one or the other. Instead, the speaker’s use of end-stop and enjambment tends to reflect his confidence and certainty (or lack thereof) as he works through difficult questions about race, identity, and belonging.
When the speaker is feeling confident about his ideas, he tends to employ end-stop. The reader can see this in lines 7 and 10:
I am twenty-two, colored, born in Winston-Salem. (7)
I am the only colored student in my class. (10)
In both lines, the speaker is making factual statements, describing in direct, straightforward language his life and his circumstances as a black student at Columbia University in the 1950s. Though the speaker will eventually question whether these statements are enough—whether they really describe his identity—they start as points of certainty and strength, things the speaker can hang onto as he plumbs the complexities of identity. The end-stops reinforce this sense of strength and certainty: they make the lines feel definite and indisputable.
Notably, the speaker uses more end-stop toward the end of the poem. Most of the last 12 lines of the poem are end-stopped, including powerful and controversial statements like the ones the reader finds in lines 31-33:
You are white—
yet a part of me, as I am a part of you.
That's American.
Here the speaker is challenging racism directly, arguing that American identity comes from the connections between different races—not the prejudice that divides them. Even as he makes this challenge, he remains confident and self-assured, and that sense of calm and strength is reflected in the end-stops. They make the lines feel definite, controlled, and unequivocal: the speaker has no doubts about what he's saying.