Old French subject pronouns (Spro) were omissible if postverbal (Foulet 1928), but not freely so (Vance 1997, Zimmermann 2014). This article addresses their partial omissibility in discourse-syntax terms, following work on partial null subject languages by Holmberg and Nikanne (2002) and Modesto (2008). An observational study of dialogic responses in 13th century prose romances is first reported, finding strong indications of covariation between the Topic/Focus status of an initial non-subject constituent and the expression/omission of post-verbal Spro. A quantitative investigation, in such texts, of preposed discourse-linked anaphoric constituents and preposed intensifiers, taken as diagnostic of Topichood and Focushood respectively, confirmed this analysis. We take null Spro to be available (i) when a null Topic operator targets left-peripheral TopicP, and (ii) with a left-peripheral Focused expression. When a discourse-linked non-subject constituent occupies TopicP, however, Spro must be overt.

This article reexamines the puzzling issue of where subjects, lexical and null,are located in Spanish and offers a novel explanation for the incompatibility ofpreverbal lexical subjects with fronted focussed constituents. Both SpecIP andthe left periphery appear to be potential landing sites for subjects, accordingto discourse-pragmatic factors. Assuming that pro is a clitic,it is argued that the aforementioned incompatibility can be captured by a simplerule: SpecIP must be empty for focus fronting to occur. This is the case withpro, which adjoins to Infl, or with postverbal subjectssince they remain in SpecVP. From this analysis it follows that: 1) the subjectfield in Spanish is less articulated than is generally assumed, 2) thedifferences between Spanish and other null subject languages with respect to theavailability of preverbal subjets can be reduced to this rule and a differentordering of focus and topic phrases, and 3) it is unnecessary to posit twodifferent topic positions.