Null referential subjects in the history of Swedish

This article is concerned with null referential subjects in Old Swedish (ca. 1225–1526), and addresses the problem of why the scope for such subjects has been reduced during the history of Swedish. Within diachronic syntax it has been a common assumption that syntactic change is caused by changes in morphology. However, this study shows that deflexion only to a limited extent can explain the loss of null referential subjects in Old Swedish, since the most striking change in their use seems to take place during Early Old Swedish (ca. 1225–1375) before the loss of person agreement: whereas referential subjects could be omitted from verb-second main clauses and subordinate clauses in Early Old Swedish, in Late Old Swedish corresponding subjectless clauses are uncommon. Within the framework of generative grammar it is argued that this is an effect of changes in movement strategies to the subject position, [Spec, IP]: whereas movement to the subject position is syntactically determined in Modern Swedish, in Early Old Swedish the corresponding move is pragmatically determined. The study is based on a corpus of approximately 193,400 words, collected from 12 Old Swedish texts.