For multicompetence to develop, the languages that constitute the lan guage processing device (LPD) and their relation to each other are very im portant. Languages of the multilingual LPD share a common underlying conceptual base (CUCB) but have no shared representation in the con stantly available interacting system (CAIS) where each language has its own separate formulator and lexicon. Language systems in the CAIS do not al low for shared processing mechanisms or strategies, however closely re lated they seem to be. The relation of the two (or more) languages is strongly affected by three variables: level of proficiency, typological close ness, and cultural distance. The level of proficiency is an obvious factor. A person who has taken French 101 will hardly develop a separate system for French. De Bot (1992) argued that the first language (LI) is usually flexible enough to add the emerging foreign language (FL) as an additional register to those already in existence.