In general, the difference in proficiency between child and adult learners
of a second language is remarkable. This difference has inspired
researchers in different fields for decades and has lead to the formulation
of the Critical Period Hypothesis for second language acquisition.
According to this hypothesis, a high level of proficiency should not be
attainable for late learners due to a biologically determined decrease in
sensitivity to language input after puberty.
The huge variation in ultimate attainment in many late learner groups in
earlier studies, has recently evoked an interest in the question of whether
there are individual late learners who manage to achieve a native level of
proficiency in a second language.
In this dissertation, this question is investigated for the area of syntax
and related to the typological distance between native and target
languages. In this study, a sentence preference task and an imitation task
were used to test highly proficient German, French and Turkish late
learners of Dutch on their command of dummy subject constructions, for
which no explicitly formulated rules are available. The use of these tasks
and constructions and the important role for the typological distance
between languages make the design of this study truly unique.
The results presented in this dissertation are not only relevant to second
language researchers, but also to neurolinguists, psycholinguists and all
late second language learners who want or need to reach an extremely high
level of proficiency in the target language.