Various studies of copula (i.e., ser and estar ) choice in Spanish in contact situations among Spanish-English bilinguals, in contexts where Spanish is not an official language (i.e., Southwestern United States) have shown that copula selection is undergoing change. The change from traditional usage is that the copula estar is becoming more accepted in an extended pre-adjectival context, especially with adjectives of size, physical appearance, age, and description and evaluation: this change was initially attributed to contact with English (Silva-Corvalán, 1986). This claim has been extended to monolingual Spanish by Gutiérrez (1992, 1994) because he found that monolingual Mexicans from the same social class as those studied by Silva-Corvalán (1986) showed the same behavior with regard to copula choice. Furthermore, Diaz-Campos & Geeslin (in press) found evidence of this phenomenon in an analysis of the spoken Spanish of Caracas, a context where Spanish is the official language and has no contact with English. Previous studies on the Spanish copula have mostly investigated settings where either Spanish is the only language spoken and the variety has been categorized as monolingual (e.g., Caracas, Venezuela), where Spanish is not the official language (e.g., Los Angeles), and contexts where Spanish is spoken widely, but English has an important role in formal education (e.g., Puerto Rico). Another context in which copula choice in Spanish has been investigated is the acquisition of Spanish as a foreign or second language. These studies have been conducted in settings where Spanish is not an official language (e.g., United States). There is a lack of evidence related to copula choice in contexts in which Spanish is an official language and English is not. The premise of this work is to help fill the gap created by the lack of studies in geographic areas where Spanish is the official language and it is in contact with English.

Three questions were asked at the onset of this study. The first one was what linguistic factors predict the use of ser and estar + adjective in the Spanish spoken by Costa Ricans in Limón. The second was what social factors predict the use of ser and estar + adjective in the Spanish spoken by Costa Ricans in Limón. The last question was whether the pattern of variation in the use of ser and estar could be considered a change in progress or a stable change. After reviewing previous empirical work done on this topic; four methodological issues were of relevance to the design of the present work. These issues are: (1) the importance of a proper power analysis during the design stages, or the probability of correctly rejecting the null hypothesis when it is false in the population, (2) the analysis of the structure of the data to select the proper statistical analysis to be used, (3) polychotomization, or categorization, of continuous variables and its effect on the power of the study, and (4) the determination of sample size to achieve an adequate level of power. The present work introduces a methodology to determine sample sizes based on power for the study of sociolinguistic data and it provides the field of sociolinguistics with a modification to the variable rule analysis that allows us to see how social predictors help explain the variance, from a statistical point of view. Differences due to social factors are obscured when the data is aggregated; therefore, a multilevel analysis in the context of logistic regression is suggested as a more powerful method for the prediction of the influence of social predictors on linguistic phenomena.

Five predictors were found to be statistically significant. These predictors were experience with the referent, adverb, subject, resultant state and adjective class. Three of these predictors, experience with the referent, resultant state and adjective class, have been shown to be very strong in the prediction of estar in different social and geographical contexts. However, these predictors are only strong predictors of estar when they are in conjunction with predictors such as predicate reading, susceptibility to change, and gradiency. It is determined that variation of copula choice in Limonese Spanish is first and foremost a syntactic phenomenon constraint by discursive and pragmatic features in accord with previous studies of copula choice in Spanish. This study shows that two varieties of Spanish can live in the same geographical area and be constrained by different social and linguistic factors. It also shows how contact with formal education, levels of bilingualism, and gender help explain variation of a syntactic structure. Monolingual Spanish behaves differently than bilingual Spanish because of access to formal education, or lack thereof, and levels of bilingualism. The extension of estar seems to be stable in the monolingual variety of Spanish while it is still ongoing in the bilingual variety of Spanish with younger speakers approximating the use of monolingual speakers.