The comparative method of variationist sociolinguistics has demonstrated that frequency changes are not reliable determinants of whether grammatical change is taking place. Frequency changes can be the result of extra-linguistic register changes, changes within the underlying grammar, or a combination (Szmrecsanyi, 2011; Tagliamonte, 2002). This work examines two variables known to vary along the written-to-spoken continuum — relative clause pronouns, and the genitive construction — across three registers of English and 100 years, with the goal of furthering our understanding of the relationship between spoken and written language. The s-genitive (i.e. Canada's government vs. the government of Canada) is on the rise in the 20th century (Hinrichs and Szmrecsanyi, 2007; Rosenbach, 2007). Statistical modeling confirms the press register leads this increase — a register change. Examination of internal linguistic constraints over time indicates simultaneous grammatical change, with the s–genitive increasing with certain inanimate subtypes. The WH-forms (who, which) of the relative pronouns have become increasingly restricted to written registers (e.g. Romaine, 1982; Tottie, 1997), leaving that as the variant used most for subject function in vernacular speech (D'Arcy and Tagliamonte 2010). Although who continues to be used for animates, which is shown to have lost any grammatical conditioning that it once had and to be undergoing lexical replacement by that for non-human subject antecedents. Unlike the genitives, though, examination of internal linguistic factors reveals no evidence of grammatical change. The methodology employed here provides a way to tease apart grammatical change from register change, with register-internal change shown to be a motivating factor in change from above. While the vernacular is ''the most systematic data for our analysis of linguistic structure'' (Labov, 1972a:208), it is not necessarily the most innovative, nor is it always the locus of change. With that in mind, this work provides a model of language change that integrates change across speech and writing.

The comparative method of variationist sociolinguistics has demonstrated that frequency changes are not reliable determinants of whether grammatical change is taking place. Frequency changes can be the result of extra-linguistic register changes, changes within the underlying grammar, or a combination (Szmrecsanyi, 2011; Tagliamonte, 2002). This work examines two variables known to vary along the written-to-spoken continuum — relative clause pronouns, and the genitive construction — across three registers of English and 100 years, with the goal of furthering our understanding of the relationship between spoken and written language. The s-genitive (i.e. Canada's government vs. the government of Canada) is on the rise in the 20th century (Hinrichs and Szmrecsanyi, 2007; Rosenbach, 2007). Statistical modeling confirms the press register leads this increase — a register change. Examination of internal linguistic constraints over time indicates simultaneous grammatical change, with the s–genitive increasing with certain inanimate subtypes. The WH-forms (who, which) of the relative pronouns have become increasingly restricted to written registers (e.g. Romaine, 1982; Tottie, 1997), leaving that as the variant used most for subject function in vernacular speech (D'Arcy and Tagliamonte 2010). Although who continues to be used for animates, which is shown to have lost any grammatical conditioning that it once had and to be undergoing lexical replacement by that for non-human subject antecedents. Unlike the genitives, though, examination of internal linguistic factors reveals no evidence of grammatical change. The methodology employed here provides a way to tease apart grammatical change from register change, with register-internal change shown to be a motivating factor in change from above. While the vernacular is ''the most systematic data for our analysis of linguistic structure'' (Labov, 1972a:208), it is not necessarily the most innovative, nor is it always the locus of change. With that in mind, this work provides a model of language change that integrates change across speech and writing.