Transcript PPT

CAS LX 500A1
Topics in Linguistics:
Language Acquisition
Week 2b. Root infinitives
Syntax 101
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Initially, children start off producing basically oneword utterances.
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Though not impossible (comprehension), it is difficult to
conclude much about syntactic knowledge at this stage.
Somewhere around one and a half years, kids will
start putting words together: Syntax… of a sort.
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Papa have it (Eve 1;6)
Marie go. (Sarah 2;3)
Eve gone (Eve 1;6)
Eve cracking nut. (Eve 1;7)
Kitty hiding (2;10)
Fraser not see him (Eve 2;0)
Eve talk funny
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This is recognizably related to English,
and even comprehensible, but it’s not the
way adults talk.
3sg -s often missing.
 Past tense -ed often missing.
 Auxiliaries have, do, and be often missing.
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In general, it seems like the grammatical
(functional) bits that are missing. Actually,
it’s kind of specific type of functional bit.
My need tea
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The things that seem to be missing are
actually things that all were considered
part of “INFL” (a.k.a. “I”, a.k.a. “T”). Tense
and subject agreement.
Even if syntactic theory has gone on to the
view that there are multiple functional
heads there (AgrSP, TP, AgrOP), it’s still
the functional part of the tree (vs. lexical).
Small Clause Hypothesis
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A very natural suggestion to make about
kids’ syntax at this stage is that it lacks the
functional layers of structure.
The sentences are “small clauses”—just
the VP, and the NP.
Various people have run with this idea. For
example, Radford, Vainikka.
“Structure building” approach to
acquisition of syntax.
Small Clause Hypothesis
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Radford (1990, 1995), Early Child English
Kids’ syntax differs from adults’ syntax:
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kids use only lexical (not functional) elements
structural sisters in kids’ trees always have a qrelation between them.
VP
NP
man
q
V
chase
“Small Clause
Hypothesis”
V’
q
car
NP
Small Clause Hypothesis
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Adults:
Kids:
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Absence of evidence for IP:
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CP—IP—VP
VP
adult syntax ≠ child syntax
No modals (repeating, kids drop them)
No auxiliaries (Mommy doing dinner)
No productive use of tense & agreement (Baby ride truck,
Mommy go, Daddy sleep)
Absence of evidence for CP:
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no complementizers (that, for, if)
no preposed auxiliary (car go?)
no wh-movement (imitating where does it go? yields go?;
spontaneous: mouse doing?)
kids bad at comprehending wh-object questions (out of
canonical order). (—What are you doing? —No.)
Small Clause Hypothesis
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Adults:
CP—IP—VP
Kids:
VP
adult syntax ≠ child syntax
 Absence of evidence for DP:
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no non-q elements
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no expletives (raining, outside cold)
no of before noun complements of nouns (cup tea)
Few determiners (Hayley draw boat, want duck, reading
book)
No possessive ’s, which may be a D.
No pronouns, which are probably D.
See also Vainikka (1993/4) for a similar proposal.
To sleep little baby
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Turns out kids talk funny around this time in lots of
languages. A particularly popular funny way to talk is
to use infinitives.
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Danish:
køre bil
German:
Thorstn das habn
French:
Dormir petit bébé
Dutch:
Earst kleine boekje lezen
‘drive[inf] car’
‘T that haveinf’
‘sleepinf little baby’
‘first little book readinf’
Further evidence for missing functional projections?
Sleeps baby
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Well, but maybe not. At the very same time as
they’re using these superfluously infinitive
verbs, they are also using finite verbs.
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Well, yeah, sure, but they hear finite verbs. But they
don’t have the clause-structural support for it yet (so
they don’t know the verbs are finite or not—that’s
information one gets from INFL). It’s just that you can
pronounce ‘sleep’ either as dort (sleeps) or as dormir
(sleep). Right? Yes?
Well, it’s easy to check. See if they can tell the
difference. See if they make errors—finite verbs
come in various kinds, do they use 1st person
agreement when they should have used 3rd?
Do kids get I/T?
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Radford points out that the overt realization of I
(T) is often missing (morphology, modals,
auxiliaries).
But is it random? Are kids just arbitrarily using
tense morphology when they do?
When tense is there, does it act like tense would
for an adult?
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Do kids differentiate between tensed and infinitive
verbs, or are these just memorized Vs at this point?
If kids differentiate between tensed and infinitive
verbs, there must be some grammatical
representation of tense.
Adult German
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Poeppel & Wexler (1993). Data: Andreas (2;1,
from CHILDES).
Adult German is SOV, V2
The finite verb (or auxiliary or modal) is the
second constituent in main clauses, following
some constituent (subject, object, or
adverbial).
 In embedded clauses, the finite verb is final.
 V2 comes about by moving the finite verb to
(head-initial) C.
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German clause structure
CP
DP
C
C+I IP
Hans kaufte
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This “second position” is
generally thought to be C,
where something else
(like the subject, or any
other XP) needs to
appear in SpecCP.
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This only happens with
finite verbs. Nonfinite
verbs remain at the end
of the sentence (after the
object).
I
—
VP
—
V
DP —
den Ball
German clause structure
CP
C
DP
IP
C+I
den hat
DP
I
Ball
Hans VP
V
V
— gekaufte
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Things other than
subjects can appear in
“first position”.
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When the tense appears
on an auxiliary, the verb
stays in place.
What to look for
in Child German
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Poeppel & Wexler found that Andreas will
sometimes use a finite verb, sometimes a
nonfinite verb.
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In adult German: finite verbs move to 2nd position,
nonfinite verbs are clause-final.
Does this also happen in kid German?
Look for a correlation between finiteness and verb
position:
ich mach das nich
I do that not
du das haben
you that have
Results
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There is a strong contingency.
Conclude: the finiteness distinction is made
correctly (at the earliest observable stage).
Conclude: children do represent tense.
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Andreas: 33 finite, 37 nonfinite verbs. 8 in both: finite, V2;
nonfinite final. Remaining verbs show no clear semantic core that
one might attribute the distribution to.
+finite
-finite
V2, not final
197
6
V final, not V2
11
37
Verb positioning =
functional categories
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In adult German, V2 comes
from V  I  C.
If we can see non-subjects
to the left of finite verbs, we
FP
know we have at least one
functional projection (above Object F
the subject, in whose Spec
F+V VP
the first position nonSubject V
subject goes).
—
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Is it really V2 (not SVO)?
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V2 (German) is different from SVO in that the
preverbal constituent need not be the subject.
Is Andreas really using adult-like V2 (not SVO)?
Look at what’s preverbal:
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Usually subject, not a big surprise.
But 19 objects before finite V2
(of 197 cases, 180 with overt subjects)
And 31 adverbs before finite V2
Conclude: Kids basically seem to be acting like
adults; their V2 is the same V2 that adults use.
Full Competence Hypothesis
(Poeppel & Wexler 1993)
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The morphosyntactic properties associated with
finiteness and attributable to the availability of
functional categories (notably head movement)
are in place.
The best model of the child data is the standard
analysis of adult German (functional projections
and all). The one exception:
Grammatical Infinitive Hypothesis:
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Matrix sentences with (clause-final) infinitives are a
legitimate structure in child German grammar.
CP
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The Full Competence Hypothesis says not only
that functional categories exist, but that the child
has access to the same functional categories
that the adult does.
In particular, CP should be there too.
Predicts what we’ve seen:
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finite verbs are in second position only
(modulo topic drop leaving them in first position)
nonfinite verbs are in final position only
subjects, objects, adverbs may all precede a finite
verb in second position.
Comparing FCH to SCH
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SCH (Radford, et al.) pointed to lack of
morphological evidence for CP.
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But P&W showed syntactic evidence for a
functional category (V2 with finite verbs) to
which V moves. Adults use CP for this.
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But they also tend not to use embedded clauses.
Which causes which?
finite verb is second
non-subjects can be first
“Absence of evidence ≠ evidence of absence.”
Andreas uses agreement correctly when he
uses it—adults use IP for that.
Is it really CP and IP?
Or just FP?
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Can we get away with only one functional
category?
The word order seems to be generable this way
so long as F is to the left of VP.
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subject can stay in SpecVP
V moves to F
non-subject could move to SpecFP.
…though people tend to believe that IP in
German is head-final (that is, German is headfinal except for CP). How do kids learn to put I
on the right once they develop CP?
Is it really CP and IP?
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Empirical argument for CP & IP:
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negation and adverbs mark the left edge of VP.
A subject in SpecVP (i.e. when a non-subject is
topicalized) should occur to the right of such elements
(if there’s just an FP).
So, look for non-subject-initial sentences with
negations or an(other) adverb.
There were 8 that matched the criteria.
All eight have the subject to the left of the
adverb/negation:
 [CP
Object C+I+V [IP Subject [VP neg/adv tSubj tV] tI ]]
Kid structures
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Hypothesis: Kids have full knowledge of the
principles and processes and constraints of
grammar. Their representations can be basically
adult-like.
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But kids seem to optionally allow infinitives as
matrix verbs (which they grow out of).
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(And when they use an infinitive, it acts like an infinitive.)
What’s happening when kids use an infinitive?
Harris & Wexler (1996)
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Child English bare stems as “OIs”?
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In the present, only morphology is 3sg -s.
Bare stem isn’t unambiguously an infinitive form.
No word order correlate to finiteness.
OIs are clearer in better inflected languages.
Does English do this too? Or is it different?
Hypotheses:
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Kids don’t “get” inflection yet; go and goes are
basically homonyms.
These are OIs, the -s is correlated with something
systematic about the child syntax.
Harris & Wexler (1996)
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Hypothesis: RIs occur when T is missing from
the structure (the rest being intact).
Experiment: Explore something that should be a
consequence of having T in the structure: do
support.
Rationale:
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Main verbs do not move in English.
Without a modal or auxiliary, T is stranded:
The verb -ed not move.
Do is inserted to save T.
Predicts: No T, no do insertion.
Harris & Wexler (1996)
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Empirically, we expect:
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She go
She goes
She not go (no T, no do)
She doesn’t go (adult, T and do)
but never
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She not goes (evidence of T, yet no do).
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Note: All should be options if kids don’t “get” inflection.
Harris & Wexler (1996)
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Looked at 10 kids from 1;6 to 4;1
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Adam, Eve, Sara (Brown), Nina (Suppes), Abe
(Kuczaj), Naomi (Sachs), Shem (Clark), April
(Higginson), Nathaniel (Snow).
Counted sentences…
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with no or not before the verb
without a modal auxiliary
with unambiguous 3sg subjects
with either -s or -ed as inflected.
Harris & Wexler (1996)
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Affirmative:
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43% inflected
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782
47
< 10% inflected
-inflec
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neg
Negative:
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aff
It not works Mom
no N. has a microphone
no goes in there
but the horse not stand ups
no goes here!
+inflec 594
5
Harris & Wexler (1996)
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Small numbers, but in the right direction.
Generalization: Considering cases with no
auxiliary, kids inflect about half the time
normally, but almost never (up to performance
errors) inflect in the negative.
If presence vs. absence of T is basically
independent of whether the sentence is
negative, we expect to find do in negatives about
as often as we see inflection in affirmatives.
Also, basically true: 37% vs. 34% in the pre-2;6
group, 73% vs. 61% in the post-2;6 group.
Harris & Wexler (1996)
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When kids inflect for tense, do they inflect for the
tense they mean?
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(Note: a nontrivial margin of error…)
Inflected verbs overwhelmingly in the right
context.
present
bare stem 771
-s
418
-ed
10
past
128
14
168
future
39
5
0
Harris & Wexler (1996)
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Last, an elicitation experiment contrasting affirmative,
never (no T dependence for adults), and not.
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Does the cow always go in the barn, or does she never go?
Does the cow go in the barn or does she not go in the barn?
Do you think he always goes or do you think he never goes?
Do you think that he goes, or don’t you think that he goes?
Processing load? Extra load of not alleviated by
leaving off the -s? If that’s the case, we’d expect never
and not to behave the same way—in fact, never might
be harder, just because it’s longer (and trigger more -s
drops).
Harris & Wexler (1996)
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Affirmatives inflected often, not inflected rarely,
never sort of inbetween.
Looking at the results in terms of whether the
question was inflected:
Kids overall tended to use inflection when there
was inflection in the question.
When the stimulus contained an -s:
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affirmative: 15 vs. 7 (68% had an -s)
never: 14 vs. 16 (48%)
not: 4 vs. 12 (25%) —quite a bit lower.
An alternative to missing T
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Much of what we’ve seen so far could also be
explained if kids sometimes use a null modal
element:
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Idea:
RI?
I want to eat pizza. I will eat pizza.
I want to eat pizza. I will eat pizza.
First question: why modals?
Second, they don’t (always) seem to mean what
they should if there is a null modal. 20/37 seem
to be clearly non-modal (according to P&W93).
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Thorsten Ball haben (T already has the ball)
Modal drop
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Can we test this another way? What are the
properties of adult modals?
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Adult modals are in position 2, regardless of what is in
position 1. If kids are dropping modals, we should expect
a certain proportion of the dropped modals to appear
with a non-subject in position 1.
But none occur—nonfinite verbs also seem to come with
initial subjects.
Why? Well, if V2 is a) movement of V to T to C, and b)
“topicalization” of something to SpecCP; and, if this is
triggered by V reaching C: There’s no need to move
anything to SpecCP if V remains unmoved. The subject
remains first.
Modal drop
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Just to be sure (since the numbers are small),
P&W check to make sure they would have
expected non-subjects in position 1 with
nonfinite verbs if the modal drop hypothesis
were true.
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17% of the verbs are infinitives
20% of the (finite) time we had non-subject
topicalization
So 3% of the time (20% of 17%) we would expect
non-subject topicalization in nonfinite contexts.
Of 251 sentences, we would have expected 8.
We saw none.
Two hypotheses about
learning (Wexler 1998)
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VEPS (very early parameter setting)
Basic parameters are set correctly at the
earliest observable stages, that is, at least
from the time that the child enters the twoword stage around 18 months of age.
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VEKI (very early knowledge of inflection)
At the earliest observable stage (two-word
stage), the child knows the grammatical and
phonological properties of many important
inflectional elements of their language.
Very Early Parameter Setting
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As soon as you can see it, kids have:
VO vs. OV order set (Swedish vs. German)
 VI [yes/no] (French vs. English)
 V2 [yes/no] (German vs. French/English)
 Null subject [yes/no] (Italian vs. Fr./E.)
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So, at least by the 2-word stage, they have
the parameters set (maybe earlier)
VEKI?
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Generally, when kids use inflection, they
use it correctly. Mismatches are
vanishingly rare.
English (Harris & Wexler 1995)
 German (Poeppel & Wexler 1993)
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Again, this is kind of contrary to what the
field had been assuming (which was: kids
are slow at, bad at, learning inflection).
Ok, but…
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So: Kids have the full functional
structure available to them, and they set
the parameters right away and know the
inflection.
What then do we make of the fact that
kids make non-adult utterances in the
face of evidence that they aren’t
learning the parameters?
KW: Certain (very specific, it turns out)
properties of the grammar mature.
Root infinitives vs. time
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The timing on root
infinitives is pretty
robust, ending around
3 years old.
NS/OI
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But some languages appear not to
undergo the “optional infinitive” stage. How
can this be consistent with a maturational
view?
OI languages: Germanic languages studied
to date (Danish, Dutch, English, Faroese,
Icelandic, Norwegian, Swedish), Irish,
Russian, Brazilian Portuguese, Czech
 Non-OI languages: Italian, Spanish, Catalan,
Tamil, Polish
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NS/OI
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What differentiates the OI and non-OI
languages?
Agreement? Italian (non-OI) has rich agreement,
but so does Icelandic (OI).
Null subjects!
Null Subject/OI Generalization:
Children in a language go through an OI stage iff
the language is not an INFL-licensed null subject
language.
NS/OI and Hebrew
(Rhee & Wexler 1995)
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Hebrew is a NS language but only in 1st
and 2nd person, non-present tense.
Everywhere else (3rd past, future, present)
subjects are obligatory.
Hebrew-learning 2-year-olds showed
optional infinitives except in 1/2-past, and
allowed null subjects elsewhere, with
infinitives.
NS/OI and Hebrew
(Rhee & Wexler 1995)
% of RIs
kids up to 1;11
null subjects
overt subjects
1/2 past/fut (NS)
0 (of 21)
0 (of 6)
else (non-NS)
32% (36/112)
0 (of 28)
all OI kids
1/2 past/fut (NS)
else (non-NS)
null subjects
0.6% (1/171)
25% (85/337)
overt subjects
1.4% (1/72)
0.6% (3/530)
Rizzi and truncated trees
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Rizzi (1993/4): Kids lack the CP=root axiom.
The result (of not having CP=root) is that kids
are allowed to have truncated structures—trees
that look like adult trees with the tops chopped
off.
Importantly: The kids don’t just leave stuff out—
they just stop the tree “early.” So, if the kid
leaves out a functional projection, s/he leaves
out all higher XPs as well.
Truncation: < TP < CP
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If kid selects anything lower than TP as
the root, the result is a root infinitive—
which can be as big as any kind of XP
below TP in the structure.
Note in particular, though, it can’t be a CP.
So: we expect that evidence of CP will
correlate with finite verbs.
Truncation: TP < AgrSP
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Pierce (1989) looking at French observed
that there are almost no root infinitives
with subject clitics—this is predicted if
these clitics are instances of subject
agreement in AgrS; if there is no TP, there
can be no AgrSP.
Truncation: TP <> NegP?
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There is some dispute in the syntax literature as to
whether the position of NegP (the projection
responsible for the negative morpheme) is higher or
lower than TP in the tree.
If NegP is higher than TP, we would expect not to find
negative root infinitives.
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But we do find negative RIs—(Pierce 1989): in the acquisition of
French, negation follows finite verbs and precedes nonfinite verbs
(that is—French kids know the movement properties of finiteness,
and thus they have the concept of finiteness).
So, is TP higher than NegP?
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Hard to say conclusively from the existing French data because there
are not many negative root infinitives—but further study could lead to
a theoretical result of this sort about the adult languages.
S O Vfin?
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Usually (Poeppel & Wexler 1993) German
kids put finite verbs in second position, and
leave nonfinite verbs at the end.
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Occasionally one finds a finite verb at the
end.
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Rizzi suggests we could look at this as an
instance of a kid choosing AgrSP as root,
where CP is necessary to trigger V2.
*Truncation?: Where train go?
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Truncation predicts: If TP is missing, then CP
should be missing.
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But Bromberg & Wexler (1995) observe that bare
verbs do appear in wh-questions in child English. Whquestions implicate CP, bare verbs implicate
something missing (TP or AgrP). So, truncation can’t
be right.
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Guasti notes that although the logic here works,
English is weird in this respect: pretty much all other
languages do accord with the prediction.
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