Lexical Frequency Effects on L2Spanish Subject Pronoun Expression

Investigations of frequency of linguistic forms have been central to usage-based models of grammar (e.g. Bybee 2001, 2010) and have advanced our understanding of developmental processes during language acquisition. Frequent forms are acquired earlier and processed more easily than infrequent forms (Ellis 2012, Lieven 2010). In addition to influencing the order in which forms emerge, frequency also plays a role in determining the distribution of forms in discourse. Learners first associate a frequent, prototypical form with a particular usage. Later they begin to use related, lowfrequency forms in ways that match the pattern of the prototype (Ellis & Collins 2009). The outcome of this process is a probabilistically constructed grammar (Bybee 2010, Ellis 1996, Lieven 2010). One example of how such usage-based models correctly predict developmental patterns comes from research on second language (L2) acquisition of the preterit and imperfect past tenses. Learners follow a trajectory whereby stative verbs, when used in the past tense, are paired with imperfective forms. Achievement verbs, on the other hand, are paired with preterit forms (Andersen 1986, BardoviHarlig 1998, Cadierno 2000, Shirai & Anderson 1995). For instance, learners of Spanish typically produce the stative verb estar as imperfect estaba, but rarely as preterit estuve. Likewise, they produce achievement verb darse cuenta as preterit me di cuenta, but rarely as imperfect me daba cuenta. The evidence for this developmental pattern is in the input, as adult native speakers frequently pair stative verbs with imperfective forms and achievement verbs with preterit forms (Andersen & Shirai 1994). Furthermore, learners rely on the evidence established between the most frequent forms and their most common usage (such as estar conjugated as estaba), and they associate other members of the same lexical class (in this case all stative verbs) with the usage patterns of the prototype (Shirai & Anderson 1995). While L2 research has clearly shown that high frequency forms are learned earlier than low frequency forms, there is still much to be discovered regarding the impact of lexical frequency on the processes underlying how grammar is learned during L2 development. For example, are there similarities between L2 learners and native speakers with respect to how frequency impacts grammar? Do frequency effects change depending on proficiency level? In the current study we further analyze the role of frequency in second language development by focusing on distributional patterns of one of the most widely studied features of Spanish, that is, subject pronoun expression (yo bailo ~ bailo). Our findings indicate that frequency impacts pronoun expression differently depending on learners’ proficiency level. During the early stages of Spanish language acquisition, learners express pronouns significantly more often with frequent than with infrequent verbs. For more advanced learners, however, frequency does not directly influence pronoun expression; instead, it mediates other linguistic variables that impact pronoun use.