The first attempt at a restrictive theory of the linear order of sentences and phrases of the world's languages, by one of the founders of cartographic syntax. Guglielmo Cinque challenges the current understanding of word order variation, which assumes that word order can be dealt with simply by putting a head either before or after its complements and modifiers. The subtle variations in word order, he says, can provide a window into understanding the deeper structure of language and are in need of a sophisticated explanation.