Subjectless Sentences in Child Language

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Subjectless Sentences in Child Language

• Paul Bloom
• 1990
• Presented by Jodi Davenport

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Hug Mommy. Play bed. Writing book. See running.
subjects
Why do children drop the subjects from sentences?
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Grammatical / Knowledge Theory
Children represent different grammars than
adults. Children may all start out with a grammar
dropping the subject (as in Spanish or Italian),
and later switch their grammar. (Hyams et.al.
1986).
Processing Theory
Children have the same grammar as adults, they
drop subjects due to performance factors. (Bloom,
this paper)
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Evidence for Processing Theory

• Length limitations occurs even when children
  imitate adult speech.
• Children omit all constituents, not just
  subjects.
• Some children dont eliminate subjects, but
  only reduce them.

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Hypothesis
If subject drop is due to processing limitations,
sentences with subjects will have shorter verb
phrases than those without.
Procedure
Examine the length of verb phrases in sentences
with and without subjects from 3 children (20
hours of recording each) stored in the CHILDES
database.
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Procedure (cont.)

• Exclude subjectless sentences acceptable in
  adult language (i.e. imperatives, put that
  down).
• Use sentences with past tense verbs (e.g.
  washed).
• Use verbs that denote cognitive states or
  involuntary acts (nonimperitives, e.g. need)

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Results
Sentences with subjects had significantly smaller
verb phrases than sentences without subjects.
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Are children omitting the subject when its
meaning can be inferred by the listener from
context?
Processing Theory no subject gt short subject gt
long subject
Pragmatic Theory no subject gt short subject
long subject
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Why are subjects omitted more frequently than
objects?
Omissions from obligatory contexts Adam Eve Sara
h Total Subjects 57 61 43 55
Objects 8 7 15 9
Processing Theory There are more processing
resources available at the end of the sentence
than at the beginning.
Since pronouns have less of a processing load
than non-pronouns, pronouns should appear more
frequently in subject position than object
position.
?
Overt non-pronoun subjects should be shorter than
overt non-pronoun objects.
?
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Possible explanations for why more subjects are
dropped
Pragmatic factors Subjects convey given
information while objects convey new info.
Save the heaviest for last A bias in language
processing that affects both children and adults.
The bias may arise from the interaction between
grammatical structure and short-term memory
within language production. (Bever, 1970).
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Summary
This paper has provided evidence in line with
processing limitations explanation of subjectless
sentences in child language.
Processing theory is a more simple explanation
for childs speech than mis-set parameters of
grammar.
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Comments
Bloom does not offer a compelling explanation for
why subjects are much more frequently dropped
than objects.
This paper lacks evidence to support the notion
that more processing resources are available at
the end of the sentence.