In second or foreign language learning, guidance is shaped by different factors: people, objectives, issues, etc. In the case of the discovery of the target language by migrants, who learn "on the job", above all for functional reasons, various studies have enabled us to better understand the language of these learners who are essentially "unguided". In this chapter, we propose to look at some of the basic principles in the study of second language acquisition before going on to look more specifically at different types of learners. We see how contact with the "natural environment" does not have the same effect on learners according to whether they are guided or not. We look at sociolinguistic factors.
