Why is ‘is’ easier than ‘-s’? Acquisition of tense/agreement morphology by child second language learners of English

This study of first-language (L1) Russian children acquiring English as a second language (L2) investigates the reasons behind omission of verbal inflection in L2 acquisition and argues for presence of functional categories in L2 grammar. Analyses of spontaneous production data show that the child L2 learners (n = 20), while omitting inflection, almost never produce incorrect tense/agreement morphology. Furthermore, the L2 learners use suppletive inflection at a significantly higher rate than affixal inflection, and overgenerate be auxiliary forms in utterances lacking progressive participles (e.g., they are help people). A grammaticality judgement task of English tense/agreement morphology similarly shows that the child L2 English learners are significantly more sensitive to the be paradigm than to inflection on thematic verbs. These findings suggest that Tense is present in the learners’ L2 grammar, and that it is instantiated through forms of the be auxiliary. It is argued that omission of inflection is due to problems with the realization of surface morphology, rather than to feature impairment, in accordance with the Missing Surface Inflection Hypothesis of Prévost and White (2000). It is furthermore suggested that L2 learners initially associate morphological agreement with verb-raising and, thus, acquire forms of be before inflectional morphology on in situ thematic verbs.