The story of English began in the fifth century when tribes from north - western Europe invaded Britain. We call these people the Anglo-Saxons. They spoke a language that was similar to modern German. Over the next thousand years, however, this language changed, because other groups of people came to live in Britain.
The first change started in about AD 800 when England was invaded by the Vikings from Norway and Denmark. They brought words like SKY , GET , HUSBAND into English. The TH sound in words like THE , THICK , BROTHER also comes from the Vikings languages. In 1066 , the Normans from northern France conquered England. The Normans spoke French. For the next three hundred years there were two languages in England. The ordinary people spoke English , but the aristocracy spoke French. The two groups did not understand each other, so the grammar that they used became much simpler. A lot of words , like PARLIAMENT , LANGUAGE or BEEF came into English from French , too. Slowly the modern language of English was born. From the 17th century , English spread to many other parts of the world. Most of the early European settlers in North America came from Britain, so English became the language of the United States and Canada. Later, the British Empire took English to Australia, New Zealand, South Africa, Asia and the Caribbean. Today, over 350 million people speak English as their first language, and billions of people use it as a second language. English has become the international language of business, entertainment , sport, transport, and the Internet.
English has borrowed a lot of words from other languages.
Here are some examples :
Bank – Italian ; tea – Chinese ; yoghurt – Turkish ; guitar – Spanish ; robot – Czech

Languages change all the time, so English is not the same all over the world. Here are some differences between British and American English :
Different spellings :
British American
centre center
colour color
Different words :
British American
lift elevator
crisps chips
autumn fall
football soccer
petrol gas