We argue that FL differs from L2 because of the sociocultural environment of the acquisition process and the linguistic background of the learners. All the other differences derive from these two important factors. In the sec ond language environment (SLE), language learners have full exposure to the target language (not only to the language system, but to its frame as well) because it is the dominant or the only language of the community. This is not the case in the foreign language environment (FLE) where stu dents’ experience and activities in the target language are almost always re stricted to the time spent in the classroom. Whereas L2 students usually (but not always) come from several countries speaking a variety of native languages, FL students almost always have one native language in common (Hammerly, 1991). From our perspective this is a crucial difference because language learners target the FL from a common linguistic background. What we examine in this book is how (if in any way) this common linguistic background is affected by the development of another linguistic system. This kind of investigation would make less sense in the SLE for several rea sons. First, the main issue here is whether FL learning can also result in the development of multicompetence. (Nobody questions that multicom
petence can develop in a SLE.) The real issue is whether an extensive expo sure to the target language system without the constant presence of the tar get language culture can result in something that is the essential consequence of L2 development. The SLE offers better conditions for stu dents to develop multicompetence than the FLE, but that is just a potential because to benefit from those conditions is mostly the responsibility of the learner. Second, students in the SLE do not have a common linguistic back ground, which makes the investigation of L2 -» LI effect quite complicated (but not impossible). Third, because we want to examine the L2 -» LI effect it is important how strongly the LI is established in the mind and what its role is in the language community. The conditions of LI use are entirely dif ferent in the SLE and the FLE. In the FLE the LI of learners usually functions as primary means of communication, but this is not the case in the SLE. LI in the SLE is more vulnerable and subject to change than it is in the FLE, where LI is usually the only means of communication.