English is an Indo-European, West Germanic language originating in England, and is the first language for most people in the United Kingdom, the United States, Canada, Australia, New Zealand, Ireland, and the Anglophone Caribbean. It is used extensively as a second language and as an official language throughout the world, especially in Commonwealth countries and in many international organizations.

Modern English is sometimes described as the first global lingua franca. English is the dominant international language in communications, science, business, aviation, entertainment, radio and diplomacy. The influence of the British Empire is the primary reason for the initial spread of the language far beyond the British Isles. Since World War II, the growing economic and cultural influence of the United States has significantly accelerated the adoption of English.

A working knowledge of English is required in certain fields, professions, and occupations. As a result, over a billion people speak English at least at a basic level (see English language learning and teaching). English is one of six official languages of the United Nations.

Approximately 375 million people speak English as their first language. English today is probably the third largest language by number of native speakers, after Mandarin Chinese and Spanish. However, when combining native and non-native speakers it is probably the most commonly spoken language in the world.