The rhupunt is one of the 24 codified Welsh meters. It focuses mainly on monorhyme, though the last line of the rhupunt will not rhyme with the rest and will usually instead be matched to a second rhupunt added to the first. As such, rhupunts were traditionally written in couplets.
The cywydd heuair fyrion is a Welsh verse form consisting simply of a couplet with two rhymed four-syllable lines. While the form can be any number of couplets, the form of the basic unit itself is one of the shortest on record at a mere eight syllables.
The cywydd deuair hirion (or “long-lined couplet”) is one of the 24 codified Welsh meters. Each line of the couplet is seven syllables and both lines rhyme, with one ending in a stressed syllable while the other ends in an unstressed syllable. This is by far the most common cywydd.
Cyhydedd naw ban is a rhymed couplet form that is numbered among the 24 codified Welsh meters. Each line written in cyhydedd naw ban is nine syllables. Cyhydedd naw ban often functions more like a basic building block to make poems out of, rather than a complete form.