Parallel poems have a similar sentence construction and structure. This means that the subject, verb and object go in the same order across multiple lines. The sentences in parallel poetry typically also use the same number of parts of speech. For example, if one line has two adjectives, the next likely will too. For example, Psalm 24:3 follows parallel construction by prefacing both lines with "who may" and presenting a question: "Who may ascend the hill of the Lord?/Who may stand in his holy place?"
Parallel poems typically feature similar rhythms across lines. Consequently, two lines may have the same number of syllables or may open with a long word and close with a single syllable. "Easy come/Easy go" is an example of such parallel rhythm construction. To be considered a parallel poem, not all of the lines have to have the same or similar rhythm, but a significant number should.
Not all parallel poems rhyme, but when they do, the rhyme scheme is predictable and even; if the first and third lines of a stanza rhyme, then the first and third lines of all stanzas will likely rhyme. Rhyming terms may also be used to contrast two opposing concepts, as is done with good and ill in John Donne's "Community": "Good we must love, and must hate ill/For ill is ill, and good good still."
Parallel poems have a pleasing, intuitive rhythm and don't offer sudden changes of rhythm or rhyme. Parallel structure can increase drama by contrasting two elements or adding more and more complex layers to the same theme. Parallel structure is a common theme in philosophical or political works because it can help build a call to action and increase the emotional weight of a piece.