Vainikka was most notable within
linguistics and SLA for developing the
Minimal Trees Hypothesis with
Martha Young-Scholten, an "important theory," where 'tree' is a metaphor of syntax for the branching structure showing how words of a
phrase or
sentence co-relate. The
hypothesis concerns what aspects of a
language learner's
first language (L1) is carried over into the
grammar of their second language (L2), in addition to mechanisms of
universal grammar that allow new acquisition to take place. Whereas many researchers lean towards a 'Full Transfer' view in which all the L1
grammar transfers - i.e. the initial state of the L2 is the final state of the first - Young-Scholten and Vainikka argued that only lexical categories (e.g. the
noun phrase) are drawn from the L1, and that functional categories (e.g. the
inflectional phrase that represents
tense) do not; rather, the learner 'grows' new ones because they start their L2 acquisition with only a 'minimal'
syntactic tree. Several competing accounts for the role of transfer and universal grammar persist in SLA; the Minimal Trees Hypothesis remains particularly controversial, and has been strongly critiqued in syntactic research on both empirical and conceptual grounds: some researchers argue that linguistic behaviour does not follow the model, and others claim that it is theoretically misconceived. For example, the idea that a component of language could be absent from the initial stage, so that the system selectively extracts only one part of the L1, is unacceptable to those who favour 'Full Transfer' rather than 'Partial Transfer'. ==See also==