How similar are adult second language learners and Spanish heritage speakers? Spanish clitics and word order

Recent studies of heritage speakers, many of whom possess incomplete knowledge of their family language, suggest that these speakers may be linguistically superior to second language (L2) learners only in phonology but not in morphosyntax. This study reexamines this claim by focusing on knowledge of clitic pronouns and word order in 24 L2 learners and 24 Spanish heritage speakers. Results of an oral production task, a written grammaticality judgment task, and a speeded comprehension task showed that, overall, heritage speakers seem to possess more nativelike knowledge of Spanish than their L2 counterparts. Implications for theories that stress the role of age and experience in L2 ultimate attainment and for the field of heritage language acquisition and teaching are discussed.