The chief device of ancient Hebrew Biblical poetry, including many of the psalms, was parallelism, a rhetorical structure in which successive lines reflected each other in grammatical structure, sound structure, notional content, or all three. Parallelism lent itself to antiphonal or call-and-response performance, which could also be reinforced by intonation. Thus, Biblical poetry relies much less on metrical feet to create rhythm, but instead creates rhythm based on much larger sound units of lines, phrases and sentences. Some classical poetry forms, such as Venpa of the Tamil language, had rigid grammars (to the point that they could be expressed as a context-free grammar) which ensured a rhythm.
The formal patterns of meter used in Modern English verse to create rhythm no longer dominate contemporary English poetry. In the case of free verse, rhythm is often organized based on looser units of cadence rather than a regular meter. Robinson Jeffers, Marianne Moore, and William Carlos Williams are three notable poets who reject the idea that regular accentual meter is critical to English poetry. Jeffers experimented with sprung rhythm as an alternative to accentual rhythm.
Poetic form is more flexible in modernist and post-modernist poetry and continues to be less structured than in previous literary eras. Many modern poets eschew recognizable structures or forms and write in free verse. Free verse is, however, not "formless" but composed of a series of more subtle, more flexible prosodic elements. Thus poetry remains, in all its styles, distinguished from prose by form; some regard for basic formal structures of poetry will be found in all varieties of free verse, however much such structures may appear to have been ignored. Similarly, in the best poetry written in classic styles there will be departures from strict form for emphasis or effect.
Light poetry, or light verse, is poetry that attempts to be humorous. Poems considered "light" are usually brief, and can be on a frivolous or serious subject, and often feature word play, including puns, adventurous rhyme and heavy alliteration. Although a few free verse poets have excelled at light verse outside the formal verse tradition, light verse in English usually obeys at least some formal conventions. Common forms include the limerick, the clerihew, and the double dactyl. 2b1af7f3a8