This morphosyntactic dissertation study compares the use of MOOD (indicative & subjunctive) in first- and second-generation Spanish speakers in New York City. The data for this study are from a transcription of naturalistic Spanish conversations with New Yorkers of different generations, representing the six primary Spanish-speaking groups in NYC: Puerto Rican, Dominican, Mexican, Ecuadorian, Colombian and Cuban. We analyze data from 26 born in Latin America and 26 born or raised in NYC, totaling 52 transcriptions. The reference model is the mood usage of first-generation newcomers, not a standard Spanish normative framework. The objective was to examine the use of mood by way of descriptive and inferential analytical methods in order to determine whether or not the second-generation bilinguals' mood grammar has changed, and if so, to establish exactly where and how it differs from the first-generation. The research questions were: 1) Does the subjunctive use of second-generation NYC bilinguals differ from that of their first-generation NYC counterparts? 2) What are the syntactic and communicative contexts in which the subjunctive is used in the first and second generations? 3) What internal and external independent variables condition mood choice in both immigrant generational groups? 4) Is the second generation's use of mood such that grammatical command of mood appears developed and systematic? Or is there evidence of an incomplete or unsystematic mood grammar? Our findings corroborate the results from other studies centered on generational U.S. subjunctive use: the second generation generates fewer subjunctives and more indicatives than the first-generation, a finding supported by statistical significance. The two generations also differ significantly concerning the internal contexts where mood manifests, but command of mood does appear intact among the majority of the second generation, thus problematizing common notions such as attrition, incomplete acquisition, and to a degree, simplification. Furthermore, analyses concerning several external variables show that the first generation appears essentially homogenous with respect to their use of mood, whereas the second-generation displays far more variability. Finally, this dissertation contributes to the variationist-sociolinguistic knowledge of Spanish grammar in bilingual settings. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]