Parallelism is a rhetorical and poetic device where similar ideas are expressed in parallel grammatical constructions, enhancing rhythm, balance, and memorability; it appears in biblical psalms, Hebrew poetry, and modern verse like Walt Whitman's to underscore themes of equality, contrast, or progression, fostering a sense of harmony and reinforcing oral traditions in literature.

Parallelism employs repeated grammatical structures across successive phrases, clauses, or lines to create rhythmic emphasis, rhetorical power, and structural coherence. This ancient technique appears throughout biblical poetry, classical rhetoric, and oral traditions worldwide. Parallelism can be syntactic (repeating sentence structures), semantic (expressing similar meanings through different words), or phonetic (repeating sound patterns). Hebrew poetry's parallel couplets present the same idea twice in varied language, as in Psalms. Whitman's long catalogs employ anaphoric parallelism, beginning successive lines identically to create accumulative force. The technique serves multiple functions: emphasis through repetition, rhythmic drive, ease of memorization, rhetorical persuasion, and structural scaffolding in free verse. Understanding degrees of parallelism—from exact repetition to loose structural echo—helps students analyze how poets build momentum and meaning. Parallelism can create expectations that poets fulfill or violate for effect. Students should note what changes across parallel structures—variations reveal emphasis and development. The technique demonstrates how syntactic choices create musical and rhetorical effects beyond semantic content alone.