Final answer:
To identify a poem's form, one must know the specific characteristics of poetic forms such as ballads, sonnets, and free verse, each having distinct stanza lengths, rhyme schemes, and rhythmic patterns.
Step-by-step explanation:
To determine which form best describes a poem, one should understand the characteristics of different poetic forms. A ballad typically consists of quatrains with a rhyme scheme of ABCB and is written in alternating lines of iambic tetrameter and iambic trimeter. A sonnet is a 14-line poem with a volta and may or may not adhere to traditional rhyme schemes in contemporary poetry. Free verse poetry does not follow prescribed rules of rhyme or rhythm and often resembles natural speech. Each poetic form dictates its own stanza length and rhyme scheme, but free verse allows a poet the freedom to decide this without following set patterns.