Thus its own associations and resonances to cause a particular effect on the reader. A basic distinction is between rhyme schemes that apply to a single stanza, and those that continue their pattern throughout an entire poem (see chain rhyme). There are also more elaborate related forms, like the sestina - which requires repetition of exact words in a complex pattern.
In English, highly repetitive rhyme schemes are unusual.[citation needed] English has more vowel sounds than Italian, for example, meaning that such a scheme would be far more restrictive for an English writer than an Italian one - there are fewer suitable words to match a given pattern. Even such schemes as the terza rima ("aba bcb cdc ded..."), used by Dante Alighieri in The Divine Comedy, have been considered too difficult for English.