1. 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 :
Disentangling bilingualism and specific
language impairment (BISLI))

2. 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.

3. OVERVIEW
OF THEORIES

4. 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)

5. 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?

6. 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)

7. 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

8. 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?

9. METHOD

10. 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)

11. 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
(23)
> 15 yrs
ca. 120 months

12. RESULTS

13. Comparing Turkish and Dutch
Percentage accuracy verb inflection in main clauses

14. 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.

15. 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

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

17. 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.

18. Verb inflection – error types in Dutch
Percentage of substitution errors

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

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

21. 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.

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

23. 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.

24. Avoidance of inflectional contexts
Percentage response types in V2 sentences

25. 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.

26. DISCUSSION
AND
CONCLUSIONS

27. 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?

28. Possible model of factors influencing vulnerability of verb inflection

29. Possible model of factors influencing vulnerability of verb inflection
Bilingualism

30. Thank You!