Lingua Franca

Lingua franca (or working language, bridge language, vehicular language) is a language systematically used to make communication possible between people not sharing a mother tongue, in particular when it is a third language, distinct from both mother tongues.

Linguas franca have been seen all over the world throughout history – vulgar Latin around the Mediterranean in the Ancient World, Swahili in East Africa, Hausa in West Africa and Plains Sign Language (not to be confused with American Sign Language) used by the aboriginal peoples of North America.