This study reports on a comparison of the use and knowledge of tense-marking morphemes in English by first language (L1), second language (L2) and specifically language-impaired (SLI) children. The objective of our research was to ascertain whether the L2 children's tense acquisition patterns were similar or dissimilar to those of the L1 and SLI groups, and whether they would fit an (Extended) Optional Infinitive profile, or an L2-based profile, e.g., the Missing Surface Inflection Hypothesis. Results showed that the L2 children had a unique profile compared with their monolingual peers, which was better characterized by the Missing Surface Inflection Hypothesis. At the same time, results reinforce the assumption underlying the (Extended) Optional Infinitive profile that internal constraints on the acquisition of tense could be a component of L1 development, with and without SLI.Research documenting the developmental parallels between second language (L2) and first language (L1) acquisition of morphosyntax has been longstanding (e.g., Dulay & Burt, 1973, 1974 see Zobl & Liceras, 1994, for review). More recently, research comparing the morphosyntax of child L2 learners to same-aged L1 learners with specific language impairment (SLI) in French and Swedish has also showed striking similarities between these two groups (Crago & Paradis, 2003;Grüter, 2005;Håkansson 2001;Paradis & Crago, 2000Paradis, 2004). Paradis (2005) found evidence for SLI-like patterns in child English L2 learners' acquisition of grammatical morphology, but to date, no direct comparison of English L2 and SLI acquisition of morphosyntax has been undertaken. The presence of overlap in the linguistic characteristics between L2 and SLI is relevant for applied concerns, such as differential diagnosis of SLI in the L2 population. Overlap is also relevant for theoretical accounts aimed at characterizing only those features of impaired grammars to the exclusion of typicallydeveloping (TD) learner grammars, among same-aged peers.On one hand, morphosyntax related to functional categories might be expected to be vulnerable across acquisition contexts on linguistic theoretical grounds, since the functional layer of the grammar could be considered the locus of much crosslinguistic variation in language-particular grammars (Paradis & Prévost, 2004). Certainly the L2 versus TD L1 and L2 versus SLI comparative research supports this expectation. On the other hand, it is reasonable to assume Corresponding author: Johanne Paradis, Department of Linguistics, University of Alberta, Edmonton, AB, T6G 2E7, Canada.
NIH Public Access Author ManuscriptAppl Psycholinguist. Author manuscript; available in PMC 2008 October 9.
NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript that shared characteristics notwithstanding, at some level there should be differences between impaired and TD learner grammars. More specifically, Paradis & Crago (2000 suggested that both French SLI and L2 acquisition have the characteristics of an (Extended) Optional...