This paper offers an examination of morphosyntactic factors that are generally understood to measure grammatical integration—and therefore used to help determine the status of other-language-origin nouns as borrowings or code-switches—through the lens of discourse, semantics, and lexical patterns. A total of 820 lone English-origin nouns surrounded by otherwise Spanish discourse are compared to Spanish and English nouns from the recorded speech of the same bilingual speakers in New Mexico. The semantic domains most open to English-origin nouns include both those traditionally expected, such as technology, and those generally thought to be unborrowable, such as kinship terms. In the case of determiner patterning, lone English-origin nouns’ propensity to occur with indefinite articles or as bare is linked to its use in the predicating function. Regarding gender, the preference for masculine assignment for lone English-origin nouns is tied to both nonreferentiality and the general patterns found in Spanish. The impact is felt here not from English, but from the conventions of the local community. Among their many functions, these nouns are best suited in this community for naming kin, classifying individuals as belonging to a certain occupation, and creating verbal compounds. It is argued that the morphosyntactic patterns found reflect the community norms, in which English-origin nouns tend to perform certain discourse functions. Systematic quantitative analysis thus reveals the powerful role of discourse referentiality of nominal forms, in tandem with local practices.