While on the subject of native speakers of English,could somebody tell me how many native speaking countries, there are in the world?
We often see schools keen to offer native speakers from just Britian ,The USA ,Australia ,New Zealand ,Canada and South Africa,yet there are at least nineteen countries in the Caribbean whose official language is English.

If that is so, shouldn't the natives of these countries be classed as native speakers of English?

Of course Chinese schools, or schools anywhere can specify whichever countries they wish to choose there teachers from,but I do wonder why ,when expressing their desire for a native speaker, they don't take advantage of a wider market and ask for native speakers from places like Trinidad,Jamiaca, Barbados and many other Caribbean islands, to teach in their schools.