In this paper we compare the code-switching (CS) patterns in three bilingual corpora collected in Wales, Miami and Patagonia, Argentina. Using the Matrix Language Framework (MLF) to do a clausebased analysis of a sample of data, we consider the impact of structural relationships and community norms on the CS patterns. We find that the ML is uniform where the language pairs have contrasting word orders, as in Welsh-English (VSO-SVO) and Welsh-Spanish (VSO-SVO) but diverse where the word order is similar as in Spanish-English (SVO-SVO). We find that the diversity of the ML in Miami is related to diversity of community norms (proficiency, identity and social network) in that community, while the uniformity of the ML in Wales is related to uniformity of community norms. This is not so clear in Patagonia, however, where we argue that bilingual speakers are so much in the minority that community norms may not hold.