Argumental null subjects in Old Icelandic

This work presents a study of argumental null subjects in Old Icelandic (OIc) that leads to a partly new picture of human impersonals and 3rd person referential pro in the language and of their theoretical consequence. OIc human impersonals have the profile of generic impersonal pronouns crosslinguistically, with formal counterparts in the generic pro of Modern Icelandic and Finnish, but different distribution and usage that contribute to understanding this impersonal class. Of particular interest are apparently nongeneric and specific uses, both of which affect the study of referential pro. OIc referential pro has been a focus of theoretical interest because of its unusual rarity and contested formal restrictions. These findings are confirmed globally, but a different picture emerges on a more fine-grained study relativised to antecedent and dependency types. Global rarity is punctuated by islands where pro is either the rule or on par with overt pronouns. Some are theoretically distinct subsystems of restricted pro-drop such as pro for reference to weapons, while others like quantifier-bound pro contribute to understanding the major pro-drop system of the language. Characteristics of the major system – preference of quantifiers for pro, availability of low-topicality antecedents, limits on nonexhaustive antecedence, and role of cohesion – suggest that it fits best in the "cohesive" pro-drop type emerging from work on 3rd person pro in Hebrew and Finnish. Throughout emphasis is placed on issues that restrictions on null subjects raise for theories of conventionalisation, such as parameter theory, which are discussed in synchronic and diachronic perspectives