Lynne Truss's popular book "Eats Shoots and Leaves" has a sub-title "A Zero Tolerance Approach". David Crystal's book, with a fine blend of humour and a great deal of expertise in the subject, illuminates the fact that grumblings about "proper usage" have a history nearly as long as the language itself. This history is traced from Old English to modern times, meeting with some wonderful characters along the way, and also looks forward to the prospects in the future for the language and the teaching of it to our children. David Crystal does not take the zero tolerance approach of Lynne Truss, but neither does he have (as sometimes accused) an 'anything goes' approach either. In the book he advocates that a standard English is incredibly useful, whilst regional and international variations colour the language to its benefit. The thesis is that context and appropriateness is the thing, and the ability to use language in this manner is the key to shaping the teaching of it in schools.
The book is not a text book, and is more of a wry, sideways look at the subject which appears to be a hot current topic. It is written in a most entertaining way, and blows away the myth that our language is on the verge of collapse. A good fun read on a subject that might appear, on the surface, a little dry. An Antedote to zero tolerance.