Paradigmatic Uniformity: Evidence from Heritage Speakers of Spanish

Subject-verb agreement mismatches have been reported in the L2 and heritage literature, usually involving infinitives, analyzed as default morphological forms for fully specified T-heads. This article explores the mechanisms behind these mismatches, testing two hypotheses: the default form and the surface-similarity hypotheses. It compares non-finite and finite S-V mismatches with subjects with different persons, testing whether similarity with other paradigmatic forms makes them more acceptable, controlling for the role of verb frequency. Participants were asked to rate sentences on a Likert scale that included (a) infinitive forms with first, second and third person subjects, and (b) third person verbal forms with first, second and third person subjects. Two stem-stressed verbs (e.g., tra.j-o ‘brought.3p.past’) and two affix-stressed verbs (e.g., me.ti-o ‘introduced.3p.past’), varying in frequency were tested. Inflectional affixes of stem-stressed verbs are similar to other forms of the paradigm both phonologically and in being unstressed (tra.j-o ‘brought.3p.past’ vs. trai.g-o ‘bring.1 p.pres’), whereas affixes of affix-stressed verbs have dissimilar stress patterns (me.ti-o ´introduced.3p.past’ vs. me.t-o ‘introduce.1p.pres’). Results show significantly higher acceptability for finite vs. non-finite non-matching, and for 1st vs. 2nd person subjects. Stem-stressed verbs showed higher acceptability ratings than affix-stressed ones, suggesting a role for surface-form correspondence, partially confirming previous findings