This study explores the use of kin terms in a corpus of Vietnamese–English bilingual spontaneous conversation. While the corpus features a range of single Vietnamese lexical items in otherwise English discourse, kin terms, as in the example below, are overwhelmingly the most frequent (accounting for 84%, 164/196, of single Vietnamese words in an English context). Borrowing or Code-switching? Traces of community norms in Vietnamese-English speechAll authorsLi Nguyen http://orcid.org/0000-0001-8632-7909https://doi.org/10.1080/07268602.2018.1510727Published online:09 October 2018Table Download CSVDisplay Table The study puts forward an empirical attempt at determining whether such items should be considered code-switches or borrowings, and the role that pragmatic norms play in shaping this linguistic behaviour. Discourse distribution of the kin terms in terms of person reference and syntactic role are used as cross-language ‘conflict sites’, to determine the level of integration of such items as a test of their status as code-switches or borrowings. This reveals that the distribution of Vietnamese kin terms in an otherwise English context mirrors that of Vietnamese kin terms in monolingual Vietnamese, and is distinct from that of English kin terms. This measure of integration suggests that these may be single-word code-switches. Nonetheless, the high frequency of use and their diffusion across the community are suggestive of borrowings. Follow-up interviews with the participants reveal specific community norms that underlie the use of these terms, namely as a linguistic resource to retain, promote and conform to community cultural practice. While the paper acknowledges the difficulty in determining the exact status of these forms based on existing criteria, it demonstrates how judicious application of empirical methodology enables us to pinpoint such strategies in studying language in contact.