On the undoing of the null subject parameter diachronically: Evidence from Greek By Brian D. Joseph, The Ohio State University The existence and origination of null subject constructions have gotten significant attention in the synchronic and diachronic literature. Thus, it is perhaps somewhat surprising that for all the consideration of how languages develop so as not to require overt subjects, there is relatively little discussion on how languages develop requirements for non-null subjects. Haiman 1974 is an exception, treating the emergence of required subjects in French as due to Germanic influence and the emergence of a Verb-Second requirement in Germanic; this idea is developed further in Haiman 1991, based on the evidence of Northern Italian varieties of Romance. In this paper, I reexamine Haiman’s specific claims regarding how a language becomes a non-null subject language, based on evidence from two constructions in Modern Greek that have developed in the past 500 years, both involving the deployment of an innovative weak subject pronoun. These constructions are a presentational deictic construction meaning ‘Here’s X / There’s X!’, and a semantically related locative interrogative construction meaning ‘Where’s X?’. I show that the subject requirement arises by the analogical creation of a weak subject pronoun out of a strong form, starting in the presentational deictic construction, with later spread to the locative interrogative. It has spread no further, thus leaving the language as generally allowing null subjects but not in this small corner of the syntax. Besides the challenges these Greek developments present for Haiman’s claims, they allow also for a broader point: large-scale effects found across the entire syntax of various languages, such as the (seemingly) inviolable non-null subject character of languages such as German or the equally (seemingly) inviolable null-subject character of languages such as Spanish, may well have originated in highly particularistic developments specific to a single construction from which generalization across broader swaths of the language occurs. Haiman, John. 1974. Targets and Syntactic Change. The Hague: Mouton, 1974. Haiman, John. 1991. From V/2 to Subject Clitics: Evidence from Northern Italian, in E. Traugott & B. Heine, eds., Approaches to Grammaticalization. Volume II. Focus on Types of Grammatical Markers. Amsterdam: John Benjamins, pp. 135-157.