Verbal inflection: why is it vulnerable in SLI? A. Baker, J. de Jong, A. Orgassa & F. Weerman Collaborators: VARIFLEX project: Elma Blom & Daniela Polišenská (NWO-research grant 254-70-010: Disentangling bilingualism and specific language impairment (BISLI))

Contents Overview of theories Data relevant to the various theories - from Turkish - from Dutch Discussion & Conclusions Wat je eigenlijk doet is niet: eerst Turks, dan NL, maar achtereenvolgens verschillende theorieen afvinken. Die werkwijze zou je hier ook kunnen aankondigen.

OVERVIEW OF THEORIES

Linguistic theories Agreement deficit account: Missing knowledge of the system underlying agreement relations. Lack of access to UG. (e.g. Clahsen 1989, 1993, 2008; van der Lely 1998, 2005) Predictions SLI children will make numerous errors. Previous data Great variation across languages. Some languages barely show verb inflection problems in SLI. Possibly only part of the paradigm affected? (Clahsen 2008)

Linguistic theories Procedural deficit account: problem in procedural memory (Ullman & Pierpoint 2005) Predictions SLI children will make similar errors to adult L2 learners since they are relying on declarative memory. Data Monolingual Dutch SLI children make different errors to L2 learners of Dutch. (de Jong 1999; Blom et al. 2006) Unlikely?

Processing theories Sparse morphology hypothesis Surface hypothesis (e.g. Leonard 1998, 2000, 2009) Predictions More problems with phonetically non-salient morphemes and those that are semantically less transparent. More problems in languages with poor morphology. Data e.g. Italian and Hebrew better than English. But total explanation? (de Jong 1999; Blom et al. 2006)

Processing theories Vulnerability feature hypothesis Predictions (e.g. Bishop 1994) Predictions Performance limitations such as sentence length or phonological complexity will negatively affect the application of the rule. Data Evidence of effects from naturalness of tokens, complexity of task. (Coady et al. 2007; Gillam et al. 2002) Crystal’s leaky bucket

Processing theories General slowing hypothesis for bilingual SLI (Windsor, Leonard) Predictions Delay compared to monolingual SLI children. Data But no evidence of delay in simultaneous bilinguals. Sequential bilinguals?

METHOD

Research variables Turkish: verb inflectional agreement Dutch: verb inflectional agreement Grammatical closure procedures used Turkish: past tense dI, 1st, 2nd, 3rd sing. Dutch: present 1st, 2nd, 3rd sing.; 1st, 2nd pl. Dutch: tested in main clauses (SVO, OVS) and subordinate clauses (SOV)

Overview populations Groups N Age range (x) Onset Dutch exposure Length Dutch exposure L1-TD 20 4;0-5;11 (4;4) 0 yrs 58 months L1-SLI 25 6;1-7;12 (7;3) 87 months L2-TD 6;7-7;11 (7;3) 1-4 yrs 63 months L2-SLI 6;8-8;3 (7;5) 1-4 yrs 62 months Adult L2 9 18-31 (23) > 15 yrs ca. 120 months

RESULTS

Comparing Turkish and Dutch Percentage accuracy verb inflection in main clauses

Comparing Turkish and Dutch Percentage accuracy verb inflection in main clauses Significant SLI effect in both languages BUT Turkish better than Dutch Support for the Sparse Morphology Hypothesis.

Comparing Turkish and Dutch Percentage accuracy verb inflection in main clauses Significant SLI effect in both languages BUT Turkish better than Dutch Support for the Sparse Morphology Hypothesis. Accuracy rate is high in both languages. Too high for a general agreement deficit to be plausible

Verb inflection – error types in Dutch Explain the various substitutes for Dutch and what the graph means

Verb inflection – error types in Dutch Significant difference between adult L2 and all child groups. Adults use more -en). No support for Procedural Deficit hypothesis.

Verb inflection – error types in Dutch Percentage of substitution errors

Verb inflection – error types in Dutch Percentage of substitution errors No part of paradigm particularly vulnerable. No support for Clahsen’s 2008 suggestion.

L2 effect in Dutch? Percentage accuracy verb inflection in main clauses

L2 effect in Dutch? Percentage accuracy verb inflection in main clauses No significant L2 effect No support for the General Slowing Hypothesis. De Four years – regel verdient wel enig bold of exclamation mark Four years of input has been sufficient to learn the rule (fairly) well.

Comparing main clauses and subordinate clauses in Dutch Percentage accuracy in main and sub. clauses NB 3rd pers. sing. only

Comparing main clauses and subordinate clauses in Dutch Percentage accuracy in main and sub. clauses NB 3rd pers. sing. only Significantly higher accuracy in subordinate clauses. Accuracy so high that rule must have be learned. Movement rule in main clauses is a source of complexity for all learners. Support for the Vulnerability Feature Hypothesis.

Avoidance of inflectional contexts Percentage response types in V2 sentences

Avoidance of inflectional contexts Percentage response types in V2 sentences Dummy auxiliaries and Root Infinitives require no verb movement. Evidence of avoidance of these contexts where inflection has to be used. Support for the Vulnerability Feature Hypothesis.

DISCUSSION AND CONCLUSIONS

What is vulnerable? Distinction necessary between learning the verb inflection rule and applying it. Word order is not highly problematic (Orgassa 2009) Computing two operations is problematic and results in: - avoidance of the V2 order - errors in inflection What causes problems with computation?

Possible model of factors influencing vulnerability of verb inflection

Possible model of factors influencing vulnerability of verb inflection Bilingualism

Thank You!