Segregation by race, ethnicity and income is a persistent feature of U.S. cities and communities, and ethnic enclaves have formed ever since immigration became more diverse. For low-skilled immigrants in particular, settling in an ethnic enclave may offer important opportunities and facilitate coping with the new environment. However, immigrant enclaves may also foster occupational segregation and retard assimilation, with the willingness to invest in language acquisition playing a key role. This paper expands on earlier work focusing on the linkage between spatial segregation and language acquisition. Using data from the 2000 U.S. Census the study stratifies immigrants by their location in one of four metropolitan areas by educational attainment and national origin in order to determine the effect of these individual characteristics on English proficiency. The probability of speaking English was found to vary across the four locales and educational attainment. Language acquisition was highest in the metropolitan area where the immigrant share is smallest, and is increasing in educational attainment.