The term Lingua Franca can refer to two phenomena. In its modern and more common usage, lingua franca refers to any interlanguage that is used for communication by parties that don't share a common tongue. A lingua franca can be a natural language, like English or Spanish, that is used in various parts of the world, often where commerce or trade takes place, and where there isn't a common language, such as in a market place or business setting. It could also be pigin¹ or creole² that has developped where two groups of people who do not share a common language have lived in close proximity for a long while. It could also be a constructed language that has been specifically designed with the aim of facilitating communications between groups of people that do not share a common language.
In its historical usage, Lingua Franca refers to Sabir, an actual pidgin language that evolved along the Mediterranean Sea coast. Based largely on Provençal and Italian, it contained many other elements from languages around including Spanish, Turkish, Greek and Arabic. Between the 11th and 19th centuries, it had been used as the interlanguage of slaves, pirates, traders, businessmen, travellers and diplomats.
| Benda ti istran plegrin:
benda, marqueta, maidin.
| Give a benda you fresh pilgrim:|
a benda, a mark or a mu'ayyidi.
Juan del Encina, 1520s
1. A pidgin is a simplified contact language that develops between two groups of people that do not share a common language. Pidgins are noted for simplifications of all kinds, phonological, grammatical and lexical. One key facet of pidgins is that they are not anyone's native language -- they develop on an ad hoc basis and can be quite fluid and labile in nature.
2. A creole is a more settled natural language that can develop as the children of pidgin language speakers grow up speaking the pidgin. A creole is thus a nativised langauge which obtains a certain level of stability. Creoles often have a lexicon based on the language of the dominant group (e.g., the ruling class of society) while the grammar is often borrowed from the subordinate group.
Many pidgins and creoles have arisen in the last 500 years or so as (in particular) European efforts at trade and colonialism have been made. Creoles based on French, Portuguese, English and Spanish, mixed usually with African languages are well documented. Other languages have also formed creoles, like Arabic and Swahili.
At the other end of this spectrum is what happens when two (or more) groups of people speaking mutually intelligble dialects or languages merge in one community. Rather than a pidgin coming into use or a creole forming, these people might develop a koine, or common language. Koineization is the process of levelling out the differences between the original dialects and forming a novel dialect in addition to the original forms.
A curious example is given in Entwisted Tongues: Comparative Creole Literatures of the Constantinople Creed, a version of the Creed used in the early 13th century during the Seige of Constantinople, perhaps representing the fusion of several mutually comprehensible Romance languages. Kretto a in deo patrem monipotante kritour sele a dera ki se voet te tout a nou se voet; e a in domnis Gizoun Kriston filiou deous l in soul ki dou per sa neiste avaoun de tout delaous klart de klarte deo veritato de par teo veritatum naisete nou faiste di oun rien patroum.