I like books about the development of language, and was hoping for good things from this book. But it didn't fully live up to those expectations.
The book is split into several sections, and the first is about the co evolution of the English language and the people of this country. He writes about the way that we have moved from the Celtic languages, and the influx of Saxon, Norse and French peoples and the way that they have shaped the words we speak today. There is a whole section on the American revolution, and the way that the American English and English have devolved; all interesting stuff, but there was a lot of history in this part.
He then goes on to cover how Britain acquired new words from other cultures - i.e. mainly by invading them. It has made our language richer, but the world was poorer for a long time because of it. Other parts of the book cover the two world wars and the influence of the British / American partnership in creating global institutions, UN IMF, that had English as its core language.
The final part covers the way that the world is going now. Lots of countries are insisting that English is a compulsory second language, Mexico for example, and when China starts to work with African countries, they converse in English. That coupled with global trade, outsourcing and so on, means that more people will speak English with an accent rather than learn a different language.
In essence, good, but not great