Basic variet(ies) and initial stages in a second language

Some 30 years ago, the comparative study of L2 acquisition pathways observed in adult migrants within the ESF project 1 (Perdue, 1993) made it possible to identify some initial stages in the acquisition of a new language in naturalistic settings.The similar development attested in the longitudinal data of learners representing ten different source/target language combinations was defined in terms of a succession of learner varieties (pre-basic, basic, post-basic), each characterized by a specific linguistic repertoire and combinatorial rules (e.g.noun-based vs. verbbased utterance structure).A crucial role in this perspective is played by the concept of Basic Variety (BV, Klein & Perdue, 1997), a formally simple but communicatively effective linguistic system, largely independent of the specificities of the languages in contact, in which lexical items of the target language are organized according to semanticpragmatic principles such as focus last / agent first.It is the emergence of morphosyntactic categories of the target language which characterizes the transition to post-basic varieties: for the language combinations studied in the ESF project, this particularly involves the marking of 'finiteness' , i.e. the development of functional oppositions through verbal morphology and the resulting restructuring of the utterance (Dietrich et al., 1995;Perdue et al., 2002; Dimroth & Starren, 2003; Hendriks, 2005;Klein & Dimroth, 2009;Becker, 2012;Klein, 2012;Véronique, 2021).However, these acquisition stages have been identified for a specific learner profile, namely adult migrants with low levels of education, who were learning the target language through immersion in the target language community.The corpus consists of oral data collected during the performance of a series of communica-