The word ‘language’ is used in at least two rather different senses. There is the political sense where each nation or tribe likes to say that it speaks a different language from its neighbours. And there is the linguistic sense where two forms of speech which are mutually intelligible are regarded as dialects of a single language. Typically, several ‘languages’ in the political sense may each be a dialect of one language in the linguistic sense. For instance, in Australia there were about 700 tribal nations but only, in total, around 260 languages (in the linguistic sense). They were typically a number of adjacent communities speaking mutually intelligible dialects of a single language. Swedish and Norwegian are separate political ‘languages’ but could be regarded as dialects of one linguistic language. The opposite situation is found more rarely – because China is one nation, people sometimes talk of Mandarin, Cantonese, Min, Wu, etc., as dialects of a single ‘language’, in the political sense; they are, in fact, not mutually intelligible and are separate languages, by the linguistic definition.

In the remainder of this book the term ‘language’ is used in its linguistic sense; two forms of speech which are mutually intelligible are regarded as dialects of one language. Once political considerations are firmly discarded, it is generally not a difficult matter to decide whether one is dealing with one language or with more than one in a given situation. A speaker of one variety can be given a spoken or written passage in another variety, and their comprehension tested by a series of questions. Certain allowances have to be made, especially for habits of pronunciation.