Morphological variability and the source of these errors have been intensely debated in SLA. A recurrent finding is that postpuberty second language (L2) learners often omit or use the wrong affix for nominal and verbal inflections in oral production but less so in written tasks. According to the missing surface inflection hypothesis, L2 learners have intact functional projections, but errors stem from problems during production only (a mapping or processing deficit). This article shows that morphological variability is also characteristic of heritage speakers (early bilinguals of ethnic minority languages) who were exposed to the family language naturalistically in early childhood but failed to acquire age-appropriate linguistic competence in the language. However, because errors in heritage speakers are more frequent in written than in oral tasks, the missing surface inflection hypothesis does not apply to them. The discussion considers how morphological errors in the two populations seem to be related to the type of experience.

The position of antecedent strategy (Carminati, 2002) claims that speakers of null-subject languages prefer to resolve intrasentential anaphora by linking pro to an antecedent in the specifier of the inflection phrase and the overt pronoun to an antecedent lower in the clause. The present study has two aims: (a) to determine whether adult early Spanish-English bilinguals (Spanish heritage speakers) and late English-Spanish bilinguals (adult second language [L2] learners of Spanish) utilize the same antecedent assignment strategies as monolingually raised Spanish speakers, and (b) to determine whether early exposure to and use of Spanish confers advantages to Spanish heritage speakers relative to L2 learners. Spanish speakers raised without English contact (n = 19), Spanish heritage speakers (n = 25), and L2 learners of Spanish (n = 19) completed an offline questionnaire that comprised complex sentences such as Juan vio a Carlos mientras pro/él caminaba en la playa “John saw Charles while he was walking on the beach.” Comprehension questions probed participants’ preferences regarding the antecedent of null and overt pronouns. The results indicate that the monolingually raised Spanish speakers showed an antecedent bias, but the heritage speakers and the L2 learners did not. Furthermore, the two groups of bilinguals differed from the controls in different ways: The heritage speakers displayed a stronger subject bias for the overt pronoun, whereas the L2 learners did not exhibit any clear antecedent biases.

It is widely recognized that the processor has a key role to play in creating and strengthening the mapping between form and meaning that is integral to language use. Adopting an emergentist approach to heritage language acquisition, the current study considers the extent to which the operation of the processor can contribute to an account of what is acquired, what is subsequently retained or lost, and what is never acquired in the first place. These questions are explored from two perspectives. First, morphosyntactic phenomena for which there is apparently substantial input are considered, with a focus on the relevance of salience, frequency, and transparency to the establishment of form-meaning mappings. Second, a phenomenon for which there appears to be relatively little input (i.e., scope) is examined with a view to understanding its fate in heritage language acquisition. In both cases, the emergentist perspective appears to offer promising insights into why heritage language learners succeed—and fail—in the way that they do.

Although claims about explicit and implicit language knowledge are central to many debates in SLA, little research has been dedicated to measuring the two knowledge types (R. Ellis, 2004, 2005). The purpose of this study was to validate the use of the battery of tests reported in Ellis (2005) to measure implicit and explicit language knowledge. Whereas Ellis (2005) tested only second-language (L2) learners (of English), this study tested both L2 and heritage language (HL) learners (of Spanish). Results showed that test scores loaded on a two-factor model, as in Ellis (2005), thereby providing construct validity for the tests, on a population of HL learners who have little explicit knowledge by virtue of the environment in which they acquired Spanish.

This study presents an investigation of oral narratives collected from heritage Egyptian and Palestinian Arabic speakers living in the United States. The focus is on a number of syntactic and morphological features in their production, such as word order, use of null subjects, selection of prepositions, agreement, and possession. The degree of codeswitching in their narratives was also investigated. The goal was to gain some insights into the Arabic linguistic competence of this group of speakers. The results show that although Arabic heritage speakers display significant competence in their heritage colloquial varieties, there are gaps in that knowledge. There also seems to be significant transfer from English, their dominant language.

This study presents and analyzes the comprehension of relative clauses in child and adult speakers of Russian, comparing monolingual controls with Russian heritage speakers (HSs) who are English-dominant. Monolingual and bilingual children demonstrate full adultlike mastery of relative clauses. Adult HSs, however, are significantly different from the monolingual adult controls and from the child HS group. This divergent performance indicates that the adult heritage grammar is not a product of the fossilization of child language. Instead, it suggests that forms existing in the baseline undergo gradual attrition over the life span of a HS. This result is consistent with observations on narrative structure in child and adult HSs (Polinsky, 2008b). Evidence from word order facts suggests that relative clause reanalysis in adult HSs cannot be attributed to transfer from English.