There are two main types of sonnet forms in the English literature: one is the Petrarchan, which consists of an octave rhyming abba abba followed by a sestet which combines two or three different rhymes; the other is the Shakespearean, organized into three quatrains and one couplet that follow the pattern abab cdcd efef gg. While Italian is a language rich in perfect rhymes, English poets find it difficult to meet the requirements of the Petrarchan rhyme system. Therefore the Shakespearean form, also known as the English sonnet, is the more frequently used of the two.