When a rhyme scheme is described with letters, the first line automatically gets designated as "A." Any other line that rhymes with the first line will also be marked as "A." Therefore, in an ABBA rhyme scheme, the first and the fourth lines rhyme, as do the second and third lines.

The sonnet was first developed in thirteenth- and fourteenth-century Italy, but became a popular form of poetry throughout Europe during the Renaissance. William Shakespeare became well known in England for his sonnets in the late sixteenth century. A sonnet typically has just fourteen strictly metered lines, with a specific structure and strict rhyme scheme.

Petrarch, who lived from 1304 to 1374, is not just famous for writing most of his poems in the sonnet form, but for widely popularizing the form across Europe. Petrarch used a standard fourteen line form with an ABBA rhyme scheme. Petrarch is considered one of the standardizers of the Italian language thanks to his immense popularity.

Iambic pentameter is most famous as the rhythm scheme used by William Shakespeare in most of his plays. The scheme features five "feet" per line, with each foot having one unstressed syllable followed by one stressed syllable. This rhythm creates a standard speaking pattern for actors and audiences to follow.