The postion of inflected verbs in early Yiddish varies between second position and positions later in the clause. Standard distributional tests establish that this reflects variation in the underlying position of infl, and that Yiddish phrase structure changed from infl-final to infl-medial. Based on clauses containing the relevant structural diagnostics, we can estimate the rate of this change. We cannot, however, determine the phrase structure of structurally ambiguous clauses (i.e., those superficially consistent with either of the phrase structures) with certainty. Nevertheless, we can use quantitative methods to estimate the likelihood of such clauses being infl-medial, and we can then use these likelihoods to provide an additional estimate of the rate of the change. Comparing both estimates reveals that they do not differ significantly. The implications of this result are briefly examined in conclusion.

Much has been written about the relationship between the usage of particular social groups and language change. This article reports on a longitudinal study of lexical variables that analyzed comparable data from the 1930s and 1990. Nearly 1,000 words were tested to determine differences in usage related to age, sex, race, education, region, and rurality. Another set of tests compared the terms used at each point in time. Yielding a list of words that exhibited both change and a pattern of social or regional variation, the results indicated that males, whites, older speakers, and speakers from rural areas use more older terms. The most educated speakers use more newer terms. These findings were reinforced by an analysis of “No Response” answers, especially on questions about obsolete or agricultural referents, which were more common among females, blacks, and urban dwellers. Most of the linguistic change was not accompanied by significant social variation.

Richness of subject-verb agreement is implicit in the functional compensation interpretation of variable second person /-s/ in Puerto Rican Spanish (PRS). Because /-s/ is not variable in Madrid Spanish (MS), richer agreement is assumed, and a lower rate of pronominal expression is expected. Central to this interpretation are effects associated with ambiguous marking of person on finite singular verbs. Although an increase of pronominal expression correlates to ambiguous marking for PRS speakers, a similar result has not been reported for MS speakers. Nonetheless, a varbrul analysis yields similar weights for this constraint in both dialects. Moreover, ambiguity effects are best understood as constraints on null subject variation that interact with switch reference. Identity of varbrul weights for constraints on pronominal and null subject variation in PRS and MS also supports the Constant Rate Hypothesis. However, the two dialects do show a diametrically opposed effect associated with nonspecific tú.

The analysis of letters written by 19th-century African Americans shows constraints on verbal -s marking which parallel those found in the writing of Scotch-Irish immigrants in the same time period and region, specifically a subject type constraint and a proximity to subject constraint. This correlation is highly suggestive for the study of the development of African American Vernacular English (AAVE). This study finds no support for a basis from a creole or from Standard English for AAVE in verbal concord and concludes that some, perhaps many, African Americans used varieties of English with little or no creole influence. Earlier studies have assumed that standard dialects of English constituted the superstrate in colonial and antebellum America; this analysis makes it clear that we must examine the features of the local varieties, black and white, before making any claims about the influences of language contact on a given variety. Further, the consistent patterns of inflections found in this study show that written documents, in particular letters written by semiliterate African Americans, are a good source for further linguistic study of 19th-century language.

Although variationists have explored the diffusion of linguistic changes from one social group to another and from one linguistic environment to another in some detail, they have done much less work on the spatial diffusion of changes. In fact, Trudgill's (1974, 1975) use of Hagerstrand's gravity model to explain in hierarchical diffusion of innovations in East Anglia and Norway was the only systematic account of spatial diffusion in the literature. This article uses data from the random sample telephone survey portion of a Survey of Oklahoma Dialects (SOD) to explore the spatial diffusion of linguistic innovations in Oklahoma. It analyzes that data using a variety of techniques of computer cartography and the General Linear Models procedure in SAS. The data clearly show that, whereas some linguistic innovations diffuse hierarchically (as linguists have long contended), others diffuse contrahierarchically, while still others diffuse in complex patterns that show characteristics of both contagious and hierarchical diffusion. An analysis of the barriers to and amplifiers of diffusion suggests that these different types of diffusion are a consequence of the different social meanings that linguistic forms carry.