The present study seeks to investigate the linguistic behavior of two Newari high castes, called Shresthas and Udas, living in Kathmandu, the capital city of Nepal, in their use of Newari, the ethnic language, and Nepali, the national language. Specifically, the study attempts to explain the hypothesis that the Hindu (Shrestha) Newars are becoming monolingual in Nepali while the Buddhist (Udas) Newars are maintaining their bilingualism in Nepali and Newari. To do so, a questionnaire was distributed to a total of 96 subjects, selected through quota sampling procedures. The questionnaire not only elicits information about the situational and societal variation in the subjects' use of Newari and Nepali but also reveals their attitudes and opinions about the differential use of these languages. Also, the participant observation method was employed to supplement and validate the responses derived from the questionnaire survey.The results from this study suggest a diglossic behavior in the Udas' use of Newari and Nepali, which, however, is remarkably different from those found in classic diglossic settings. This, in turn, leads to a reexamination of Ferguson's concept of diglossia. The Shresthas, on the other hand, frequently alternate between Newari and Nepali regardless of situation. Such linguistic differences between these two groups are related to their varied social networks and relationships; the Udas Newars' greater use of Newari is due to their closed social networks while the Shresthas' greater use of Nepali is due to their open social networks.The data on the analysis of the subjects' attitudes and opinions toward Nepali and Newari indicate that the Udas Newars are positive and favorable toward Newari while the Shresthas are ambivalent in their opinions toward these languages. This study, therefore, emphasizes a strong need for bilingual education in the country.The results of the present study show that the Udas' use of Newari exclusively at home and with children is a major factor in its retention. Among the Shresthas, it is rapidly losing ground to Nepali. Newari then is gradually dying away among the Shresthas, and will continually do so in the absence of institutional support. / Department of English