Children categorize native-accented speakers as local and non-native-accented speakers as foreign, suggesting they use accent (i.e., phonological proficiency) to determine social group membership. However, it is unclear if accent is the strongest – and only – group marker children use to determine social group membership, or whether other aspects of language, such as syntax and semantics, are also important markers. To test this, five- to eight-year-old monolingual English-speaking children were asked to judge whether individuals who varied in phonological, syntactic, and semantic proficiency were local or foreign. Children were also asked which individual they wanted as a friend. Children prioritized phonological proficiency over syntactic and semantic proficiency to determine social group membership. However, with age, children begin to shift toward prioritizing syntactic and semantic proficiency over phonological proficiency in their friendship decisions, suggesting that the capacity to integrate different aspects of a speaker's linguistic proficiency changes with development.