Modern English, sometimes described as the first global lingua franca, is the dominant language or in some instances even the required international language of communications, science, information technology, business, aviation, entertainment, radio and diplomacy. Its spread beyond the British Isles began with the growth of the British Empire, and by the late 19th century its reach was truly global. Following the British colonization of North America, it became the dominant language in the United States and in Canada. The growing economic and cultural influence of the US and its status as a global superpower since World War II have significantly accelerated the language's spread across the planet. English replaced German as the dominant language of science Nobel Prize laureates during the second half of the 20th century (compare the Evolution of Nobel Prizes by country).

A working knowledge of English has become a requirement in a number of fields, occupations and professions such as medicine and computing; as a consequence over a billion people speak English to at least a basic level (see English language learning and teaching). It is one of six official languages of the United Nations.

One impact of the growth of English has been to reduce native linguistic diversity in many parts of the world, and its influence continues to play an important role in language attrition. Conversely the natural internal variety of English along with creoles and pidgins have the potential to produce new distinct languages from English over time.