Dual competence in dual language learners

Abstract This chapter focuses on grammatical variability in object clitic placement (omission and clitic climbing) and morphology (gender and number) in child heritage Spanish. Implementing Wexler’s (2003) Clitic Acquisition Theory (CAT), original corpus data from 60 U.S. Spanish heritage speakers (SHS), ages 4–7, are analyzed and compared to previous research on adult L1/L2/child L1 and bilingual acquisition on clitic expression and acceptability judgments. Results show SHS at all proficiency levels produce clitics to some degree; however compared to Wexler (2003) and subsequent CAT studies, SHS demonstrate ongoing clitic optionality. A high percentage of this variability is grammatical: for instance, no substantial difference in SHS frequencies for proclisis or enclisis occurs. In the spirit of L2 work by Slabakova, Rothman and Kempchinsky (2011), the Underlying and Surface Competence (Duffield, 2003) is tested as a generative-based account of variability in more mature child grammars, complementing CAT. The dual competence model provides a finer-grained snapshot of ‘adult-like’ Spanish clitic expression in children.