This article surveys the ways that subordinate clauses and alternatives are used in English, with relation to style, variation and register. A first section looks at what a clause is and does; later sections consider how clauses and their alternatives are used in some significant areas of formal and informal English. The main varieties of language dealt with are: science, the law, advertising and newspapers. Clauses and alternatives to clauses play a significant role in determining the style of a piece of writing - an important factor that writers and translators must bear in mind when trying to provide the right framework for expressing ideas.