The study examines the natural progression in the acquisition of an essential aspect of German sentence structure - verb positioning - by elementary-school native speakers of Turkish and Russian. With reference to four long-term studies, the author shows how the learners form hypotheses on the complex input of German as a target language and the role played by their knowledge of their mother tongue in the evolution of interim grammars. A theoretical section describes contemporary theories of second language acquisition and discusses their explanatory power in the light of the empirical findings produced by the study.
