_Cuartetas_, properly so called, are strophes of four eight-syllable
verses, of which the second verse rhymes (or is in assonance) with the
fourth. _Cuarteta_ is likewise a general name given to strophes of
four verses.

_Serventesios_ are strophes of four hendecasyllables, of which the
first rhymes or assonates with the third, and the second with the
fourth.

_Redondillas_ are strophes of four eight-syllable (or sometimes
six-syllable) verses which rhyme as follows: a b b a.

_Cuartetos_ are strophes of four hendecasyllables with the
rhyme-scheme a b b a. It is not customary to put a final word that is
_aguda_ in the uneven verses of compositions written in
hendecasyllables, or in verses that rhyme with them. Sometimes the
four verses are esdrújulos.

_Romances_, which are the most used of all forms, need not be written
in _cuartetas_. It is sufficient that the even verses be in assonance
and the uneven verses free. Romances, properly so called, are composed
of octosyllabic verses.

_Romancillos_ are romances composed of verses with less than eight
syllables.

_Romances heróicos_ are romances composed of hendecasyllabic verses,
all of which are _llanos_.

_Quintillas_ are combinations of five verses that have but two rhymes,