There was, apparently, in the 18th Century, a native American chief who was a prodigy in languages. In the year after his first European contact he became fluent in Spanish, Italian, English and French, and was taken to England as a kind of curiosity. At dinner one night at some university college or other, when the subject turned to the differences between languages, he was asked "What is the grammar of your own language?" He replied, "My language has no grammar." The story may or may not be true, but illustrates an always true phenomenon which everyone encounters the moment they start to learn a new language: the grammar of our own language is invisible to us, except when some teacher drearily and pointlessly insists on showing us, although those of other languages are powerfully and bafflingly obvious the moment we encounter them. It's not just linguistic grammars, of course. Grammar is the set of rules and principles by which a language is organised,