The development of the syntax-information structure interface

Recent acquisitional studies reveal that formal properties at the lexicon-syntax interface are in place before discursive properties at the syntax-discourse interface. It has been argued that this phenomenon results from learners’ deficits with interpretable discursive features like [focus]. This study claims that the phenomenon derives from learners’ deficits with the un-interpretable formal features responsible for regulating the occurrence of discursive focus, whereas learners’ representation of interpretable focus features are intact. This claimwas tested by conducting a study with Greek learners of non-native Spanish at three proficiency levels. Learners judged Subject-Verb and Verb-Subject order with intransitives (unergatives and unaccusatives), which is constrained both formally (Unaccusative Hypothesis at the lexicon-syntax interface) and discursively (presentational focus at the syntax-discourse interface). Results confirm that, while the general ‘syntax-before-discourse’ observation is correct, learners’ source of persistent deficits with discursive properties derives from the uninterpretable feature that regulates the syntactic realisation of focus. This implies that learners are sensitive to the (interpretable) [focus] feature, but are unable to grammaticalise it syntactically.