A sonnet usually has how many lines?

A Sonnet is a poem of an expressive thought or idea made up of 14 lines, each being 10 syllables long. Its rhymes are arranged according to one of the schemes – Italian, where eight lines called an octave consisting of two quatrains which normally open the poem as the question are followed by six lines called a sestet that are the answer, or the more common English which is three quatrains followed by a rhyming couplet.

The term sonnet is derived from the Italian word sonetto (from Old Provençal sonet a little poem, from son song, from Latin sonus a sound). By the thirteenth century it signified a poem of fourteen lines that follows a strict rhyme scheme and specific structure. Conventions associated with the sonnet have evolved over its history. Writers of sonnets are sometimes called "sonneteers", although the term can be used derisively.