Check out the other poems in Plath's book Ariel, and you'll see that our gal Sylvia was a fan of short lines. Seriously, check 'em out: we recommend "Lady Lazarus" and "Daddy" for starters. Plath's lines in these poems barely have more than three or four words per line, and some have just one.
But the cool thing about Plath is that, though her lines may look spare on the page, when you read them aloud, you discover that they're actually really dense in terms of their sounds. As we discuss in the "Sound Check," there are tons of rhymes and other kinds of sonic repetition. This rare combo of sparseness and density characterizes many of Plath's poems, and almost all of her best-known poems. Plath really knew how to pack a poetic punch. Pow.