Throughout history, events great and small have left their mark on the way we speak. Columbus's discovery of America introduced to Europe new foodstuffs such as chilli and chocolate - and the words that described them. The Normans gave us the feudal system and curfews, while the flourishing of Dutch art in the seventeenth century introduced easels, etchings and landscapes. Before the 1970s green was a colour with connotations of naivety rather than ecology and until 1990 webs were mostly attached to spiders.