In this thesis I tried to give a detailed insight of the differences between British, American and Australian English. First I wrote about the history of these three varieties and how numerous expeditions and migrations influenced them because that is the main reason why there are so many differences between them. After that, I explained the differences in vocabulary, pronunciation, stress, spelling, punctuation, verb forms, abbreviations, dative and genitive constructions and even in literature. A lot of people do not even know that there are so many differences between British, American and Australian English, especially the ones who are not native speakers of English. All of the mentioned differences are only the ones which have occurred until today, but that does not mean that they will not change anymore. Language is something that changes from one day to another where a few years can make a huge difference. Every day people are moving from one country to another and in this way, they are influencing the language of the natives and the same thing is happening with the English language too. Each day new words are being created and in a hundred years the English language might be completely different from the English we know today.