Recently I was checking some of my students' school essays and found they have used the three words England, Britain / Great Britain and United Kingdom (UK) almost interchangeably. Many others make similar mistakes, not knowing that these three terms are not exactly synonymous.
The United Kingdom
The United Kingdom or UK is constituted of four countries. These are - England, Scotland, Wales and Northern Ireland.
In fact the actual name of UK is The United Kingdom of Great Britain and Northern Ireland.
Britain (Great Britain)
Leave out Northern Ireland from the United Kingdom and you have Britain. The concept of the United Kingdom is political; while the concept of Britain is mostly geographical - the three countries (England, Scotland and Wales) that constitute Britain all share a single island.
Britain was previously also called Great Britain mainly for two reasons. In the medieval ages the English landlords had their properties in Britanny which is now in France; to distinguish from those overseas lands the home country was called Great Britain.
Later, when Britain became one of the most dominant colonisers, the name Great Britain helped manifest its power with a colonial undertone.
As suggested above, England is only a part of both the United Kingdom and Britain. The English nation is constitued of England and Wales. Wales is politically a part of England, but it is geographically distinguished.
1. The English we speak is the language in The United Kingdom
[suggesting that it is the standard written language of England, Scotland, Wales and Northern Ireland though there are thousands of dialects and registers]
2. Great Britain was the most dominant colonial power in the twentieth century
[Suggesting that Northern Ireland was not a coloniser nation, in fact it was colonised itself]
3. England has good chances in the upcoming FIFA world cup
[Suggesting that the country has talented footballers]