A lingua franca
is a language systematically used to make communication possible between people not sharing a first language, in particular when it is a third language, distinct from both speakers' first languages. Examples of lingua francas are numerous, and exist on every continent. The most obvious example is English
, which is the current lingua franca of international business, science, technology and aviation. There are many other lingua francas centralized on particular regions, such as Arabic
The popularity of languages changes over time, and there are many lingua francas that are of historical importance. These include French
, which was the language of European diplomacy from the 17th century until the mid-20th century, and Classical Chinese
, which served as both the written lingua franca and the diplomatic language in Far East Asia until the early 20th century. French and Chinese are still significant lingua francas today.
International auxiliary languages such as Esperanto have historically had such a low level of adoption and use that they can only be described as potential rather than functioning lingua francas.