The term “parallel” refers to two things that are analogous to each other. In poetry, parallel lines can be analogous by way of structure or content. Poets use parallelism for a variety of reasons, perhaps the main one being for emphasis. But parallel lines can also affect poetry differently, giving them a childlike feel, as in William Blake’s poem “The Lamb”; building suspense, as in Elizabeth Barrett Browning’s “How Do I Love Thee?”; or creating rhythm, as in Gwendolyn Brooks' "We Real Cool." No hard and fast rules govern the use of parallelism in poetry, and poets can use the technique in any way they like to convey their message.
“The Lamb” by William Blake
The simplicity of the repetition and rhyme in Blake’s “The Lamb” gives the poem a childlike, nursery-rhyme feel: “Little Lamb who made thee / Dost thou know who made thee.” Several lines later Blake uses the most basic of parallels – an exact repetition: "Little Lamb I’ll tell thee, / Little Lamb I’ll tell thee!" These simple phrases emphasize the tender, lamb-like nature of God, which Blake endeavors to illustrate in this poem. Additionally, the structural technique of parallelism accentuates the more abstract parallel idea that Blake is trying to convey, that both God and children are like lambs.
"How Do I Love Thee?" by Elizabeth Barrett Browning
The most prominent parallel lines in Barrett Browning's famous romantic poem are the following: "I love thee freely, as men strive for right. / I love thee purely, as they turn from praise." But actually, the motif “I love thee” followed by an explanatory clause finds much repetition throughout the poem, as it answers the question of the title (“How Do I Love Thee?”) in list-like form. These two particular lines contain the exact same parts of speech and the same number of beats, and the repetition of “I love thee” creates a rhythm that builds to a climax, where Barrett Browning compares the strength of her love to life itself and its permanence even after death.
"We Real Cool" by Gwendolyn Brooks
This sharp little poem consists of four stanzas, each containing two parallel lines: "We real cool. We / Left school. We." Each line of each parallel follows the same basic structure, beginning with a pronoun and ending with a noun or adverb, except for the first line, which ends with an adjective. Each line has three beats. The short, clipped parallel sentences give the poem a bit of a jingle or waltz feel. In an interview with George Stavros on the University of Illinois' website, Brooks states that she ended each line with “We” to show that the speakers feel hesitant about their identities.
Hebrew poets, particularly in the Bible, used parallelism in their writing. Hebraic parallelism, however, has more to do with content rather than structure. For example, in Psalm 24:7, which states, “Lift up your heads, you gates; / Be lifted up, you ancient doors,” both “lifted up” is repeated and the idea of entrances (“gates” and “doors”). Psalm 24 is full of parallel ideas, where the second line offers a further explanation or another wording of the same idea for emphasis and aesthetic interest.