SUMMARY
This study is a case study that covers the presentation formats for language choice on the speech community of Acehnese based upon family domains in bilingual Indonesian speech behavior. The sources of variance are between Aceh and Indonesian languages in Medan. The parameters that are being used first through language choice between Indonesian, Indonesian/Acehnese, and Acehnese relating to the role relationship between husband to wife; father, mother and their sons and daughters. The second one is related to speech situation such as arguing, advising, chatting, and persuading. The method approach is quantitative descriptive and was employed by the samples of 200 persons. The result shows that the average persentage of the language choice in every single speech situation among the husbands to the wives was 86% and the wives to the husbands was 82% dominantly Acehnese. The average percentage of the language choice among sons and daughters to their parents or vice versa was 76 % constantly mixing language; Acehnese/Indonesian in all of speech situations. The result of this study showed that mostly the husbands and the wives maintain their tribe language well. The result found that most of the children of Acehnese never totally leave their tribe language, even they live in Medan as a big city.