Verb agreement in Turkish-Dutch
bilingual children with SLI
Jan de Jong, Antje Orgassa, Nazife
Çavuş, Anne Baker, Fred Weerman
1
Research issue
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Verb morphology is vulnerable in SLI.
Explanations: locus of the problem either in
representation or processing
Explanations are based on crosslinguistic
differences or commonalities in symptoms
Are crosslinguistic differences found when the
subjects are the same (bilingual) children?
Which theory explains the symptoms best?
2
Outline of the talk



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Two theories of SLI
Characteristics of Dutch and Turkish
Predictions for SLI in two languages: Dutch
and Turkish
The Dutch study
The Turkish study
Comparing the results from both studies
Conclusions
3
SLI in Turkish and Dutch: two
theories on SLI will be tested

SLI is a representational deficit


Agreement Deficit hypothesis (Clahsen)
SLI is a processing deficit

Sparse morphology hypothesis (Leonard)
4
Characteristics of Dutch and Turkish
Turkish
Agreement is marked
Dutch
Agreement is marked
Pro-drop
Non-pro-drop
Inflectional paradigm
uniform
Inflectional paradigm
not uniform
Sparse morphology
Rich morphology
5
SLI in Turkish and Dutch: what do
theories on SLI predict?

Agreement Deficit hypothesis

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Agreement problems will be found in both
languages
Sparse morphology hypothesis

Morphological problems will be more
serious in Dutch than in Turkish
6
Possible outcomes and their
interpretation
Turkish – / Dutch –
Turkish + / Dutch –
Agreement deficit hypothesis
supported
Turkish – / Dutch +
Turkish + / Dutch +
7
Possible outcomes and their
interpretation
Turkish – / Dutch –
Turkish + / Dutch –
Agreement deficit hypothesis
supported
Agreement deficit hypothesis
falsified
Turkish – / Dutch +
Turkish + / Dutch +
Agreement deficit hypothesis
falsified
Agreement deficit hypothesis
falsified
8
Possible outcomes and their
interpretation
Turkish – / Dutch –
Turkish + / Dutch –
Agreement deficit hypothesis
supported
Sparse morphology hypothesis
supported
Agreement deficit hypothesis
falsified
Turkish – / Dutch +
Turkish + / Dutch +
Agreement deficit hypothesis
falsified
Agreement deficit hypothesis
falsified
9
Possible outcomes and their
interpretation
Turkish – / Dutch –
Turkish + / Dutch –
Sparse morphology hypothesis
falsified
Agreement deficit hypothesis
supported
Sparse morphology hypothesis
supported
Agreement deficit hypothesis
falsified
Turkish – / Dutch +
Turkish + / Dutch +
Sparse morphology hypothesis
falsified
Agreement deficit hypothesis
falsified
Agreement deficit hypothesis
falsified
10
Possible outcomes and their
interpretation
Turkish – / Dutch –
Turkish + / Dutch –
Sparse morphology hypothesis
falsified
Agreement deficit hypothesis
supported
Sparse morphology hypothesis
supported
Agreement deficit hypothesis
falsified
Turkish – / Dutch +
Turkish + / Dutch +
Sparse morphology hypothesis
falsified
Agreement deficit hypothesis
falsified
Sparse morphology hypothesis
neither falsified nor supported
Agreement deficit hypothesis
falsified
11
Subjects
Group
Number
Average
Age
Age
range
Data from:
Bilingual SLI
20
7;4
5;11 – 8;5
Turkish &
Dutch
Bilingual typical
20
7;1
5;9 – 8;4
Turkish &
Dutch
12
The Dutch study: Inflectional
paradigm
context
lezen ‘to read’
suffix
1sg
stem + ø
ik lees
‘I read’
2sg
stem + t
jij leest
‘you read’
3sg
stem + t
hij/ zij leest
‘he/ she reads’
1pl-3pl
stem + en
wij/ jullie/ zij lezen ‘we/ you/ they read’
13
Dutch
The Dutch study: Task ilustration
Antje leest
een boek
Antje reads-3sg a book
en
Jan leest
een krant
and
Jan reads-3sg a newspaper
14
Dutch
The Dutch study: Results correctness
Verb inflection (%)
Bilingual Typical
88
(303)
Bilingual SLI
77
(250)
15
Dutch
The Dutch experiment: conclusions

Children with SLI produce more
incorrect forms than children without
SLI in their L2
16
The Turkish study: inflectional
paradigm
okumak ‘to read’
-dI- (PAST evidenced)
context
suffix
1 sg
stem + dI + m
Oku-du-m
2 sg
stem + dI + n
Oku-du-n
3 sg
stem + dI + Ø
Oku-du- Ø
1 pl
stem + dI + k
Oku-du-k
‘we read’
2pl
stem + dI + nuz
Oku-du-nuz
‘you read’
3 pl
stem + dI + lar
Oku-du-lar
‘they read’
‘I read’
‘you read’
‘he/ she read’
17
The Turkish study: task illustration



Anne
ben portakal-ı _____ (sık-tı-m).
Mummy I
orange-ACC ____ (press-PST.DI-1SG)
Mummy, I have squeezed an orange.
18
Turkish
The Turkish study: Results correctness
Verb inflection (%)
Bilingual Typical
100
(251)
Bilingual SLI
93
(295)
19
Turkish
The Turkish study

Children with SLI produce more
incorrect forms than children without
SLI in their L1
20
Turkish versus Dutch: correctness (%)
Turkish
Dutch
Bilingual
typical
100
88
Bilingual SLI
93
77
21
Turkish versus Dutch: conclusion for
the group

More errors in Dutch than in Turkish

Crosslinguistic difference


The Sparse Morphology hypothesis is
confirmed
The Agreement Deficit hypothesis is
disconfirmed
22
Comparing the individual patterns
within the SLI group (+ = >90% correct)
Turkish –/ Dutch –
Turkish +/ Dutch -
n=3
n = 12
Turkish –/ Dutch +
Turkish +/ Dutch +
n=2
n=3
23
Explaining the individual patterns
within the SLI group (+ =>90% correct)
Turkish –/ Dutch –
Turkish +/ Dutch -
n=3
n = 12
Supports Missing Agreement
hypothesis
Turkish –/ Dutch +
Turkish +/ Dutch +
n=2
n=3
24
Explaining the individual patterns
within the SLI group (+ =>90% correct)
Turkish –/ Dutch –
Turkish +/ Dutch -
n=3
n = 12
Supports Missing Agreement
hypothesis
Supports Sparse Morphology
hypothesis
Turkish –/ Dutch +
Turkish +/ Dutch +
n=2
n=3
25
Explaining the individual patterns
within the SLI group (+ =>90% correct)
Turkish –/ Dutch –
Turkish +/ Dutch -
n=3
n = 12
Supports Missing Agreement
hypothesis
Supports Sparse Morphology
hypothesis
Turkish –/ Dutch +
Turkish +/ Dutch +
n=2
n=3
Differential input from two
languages (D>T)
26
Explaining the individual patterns
within the SLI group (+ =>90% correct)
Turkish –/ Dutch –
Turkish +/ Dutch -
n=3
n = 12
Supports Missing Agreement
hypothesis
Supports Sparse Morphology
hypothesis
Turkish –/ Dutch +
Turkish +/ Dutch +
n=2
n=3
Differential input from two
languages (D>T)
27
Explaining the individual patterns
within the SLI group (+ =>90% correct)
Turkish –/ Dutch –
Turkish +/ Dutch -
n=3
n = 12
Supports Missing Agreement
hypothesis
Supports Sparse Morphology
hypothesis
Turkish –/ Dutch +
Turkish +/ Dutch +
n=2
n=3
Differential input from two
languages (D>T)
Misdiagnosis?
28
Conclusions

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The crosslinguistic differences in the group
comparison support processing-based explanations
like the Sparse morphology hypothesis and do not
support the Agreement Deficit hypothesis
The individual patterns support processing-based
explanations like the Sparse morphology hypothesis
and do not support the Agreement Deficit hypothesis
The individual differences also highlight the
importance of considering L2 factors (like language
input, language dominance) in understanding
bilingual SLI
29
What about the typical bilingual
group? (+ = >90% correct)
Turkish –/ Dutch –
Turkish +/ Dutch -
n=0
n=8
Supports Sparse Morphology
hypothesis?
Differential input from two
languages (T>D)?
Turkish –/ Dutch +
Turkish +/ Dutch +
n=0
n = 12
30