Predictors of Past Tense Marking by Lexical Aspect Category
Brian K. Weiler  C. Melanie Schuele
Vanderbilt University School of Medicine
INTRODUCTION
PARTICIPANTS
METHODS
RESULTS
By the age of five, children with typical language skills mark
finiteness on past tense at levels approaching mastery (Rice &
Wexler, 1996). Prior to mastery, young children sometimes produce
bare verb stems in contexts where inflected forms are obligatory in
the adult language (e.g., he jump vs he jumped) . A consideration of
lexical aspect may help account for why some past-reference verbs
are tense marked while others are not. Lexical aspect relates to the
temporal properties of situations that individual verbs describe.
Fifty-two preschool children, 37 to 61 months, participated in the initial
study. Participants demonstrated typical language skills (see Table 2).
They were identified from a broader pool of 100 children. Participants
were selected for variable past tense marking across sixteen elicited
past tense verb targets (i.e., at least one marked and one omitted in
obligatory contexts). All children produced word final /d/ and /t/ on a
phonological probe. The children were recruited from four preschools.
Demographic information received from 83% of the final participant
pool indicated that 98% of the children had at least one parent with a
college education and that 98% were Caucasian. All participants were
monolingual speakers of mainstream English dialect.
In the present analysis, the two verb-level predictors (see Table 5) were
defined as follows: Stem-final phonology was identified as either
alveolar stop consonant or other. Adult lexical log-frequency values for
each inflected verb target were determined through use of the CHILDES
Parental Corpus (Li & Shirai, 2000; MacWhinney, 2000).
Table 6. Hierarchical Multiple Linear Regression Analysis for
Predictors of Past Tense Marking on Achievements
Table 1. LEXICAL ASPECT CATEGORIES
Category
Temporal properties
Example utterance
Achievement
[- durative] [+ dynamic] [+ telic]
She blew out the
candle.
Accomplishment
[+ durative] [+ dynamic] [+ telic]
He tied his shoes.
Age in Months
SD
48.94
7.01
PPVT-III SS
110.48
11.31
PLS-4 Total SS
116.61
13.07
METHODS
The study involved secondary analysis of data collected for an
investigation of complex syntax in typical language learners (Schuele,
2006). Child responses to 16 verb targets from the past tense probe of
the Rice/Wexler Test of Early Grammatical Impairment (TEGI; Rice &
Wexler, 2001) were analyzed. The 16 TEGI verb targets were selected
for their lexical aspect categorization as either Accomplishment or
Achievement using Shirai and Anderson’s (1995) coding scheme (see
Table 3). Category assignment by the first author and a graduate
assistant met complete independent agreement.
The likelihood of children’s use of past tense morphology in
obligatory contexts may be explained, in part, by the additive
influence of several properties of the target verb (Owen, 2010). For
example, Marchman, Wulfeck, and Ellis Weismer (1999) found that
children were more likely to omit past tense morphology on verbs
with alveolar stop consonant bare stem phonology and low
frequencies for adult past tense use. Past tense morphology also
has been shown to be influenced by a combination verb-level
phonological (obstruent vs. non-obstruent coda) and lexical aspect
(telic vs. atelic) factors (Johnson & Morris, 2007).
PURPOSE
The current study is a retrospective analysis of past tense marking
among typical preschoolers who have not mastered past tense
morphology (Weiler & Schuele, 2011). We examined the predictive
nature of two factors known to impact variable tense marking, stemfinal verb phonology and adult lexical frequency, on elicited past
tense productions across lexical aspect categories differing on the
durative temporal property. The purpose of this analysis was to
explore whether verb-level predictors of past tense marking behave
similarly or differently relative to lexical aspect.
clean, climb, made, write, paint,
pick, eat, brush, plant, tie
Table 4. CREDITED CHILD RESPONSES
Correct regular or irregular past
He kicked. She made.
Over-generalization of regular past
She maked.
Over-regularization of irregular past
She maded.
Regular past over-marked
He jumped-ed
blow
1.785
91.8%
make
3.066
92.6%
jump
2.009
90.2%
tie
1.881
91.8%
catch
2.340
87.9%
pick
2.286
90.9%
kick
1.447
82.1%
climb
1.949
88.1%
give
2.816
70.7%
clean
lift*
1.663
15.6%
brush
She catched-ed
1.322
81.0%
-68.94
9.38
-.965**
Stem final phonology
-72.84
9.44
-1.019**
Adult lexical logfrequency value
-9.357
7.72
.312
77.1%
paint*
1.623
63.0%
plant*
1.279
58.8%
1.869
Note. R2 = .931 for Step 1; Δ R2 = .023 for Step 2.
**p < .005.
Table 7. Hierarchical Multiple Linear Regression Analysis for
Predictors of Past Tense Marking on Accomplishments
52.8%
β
B
SE B
Stem final phonology
-24.56
4.94
-.869**
Stem final phonology
-22.455
3.93
-.795**
9.25
3.73
.346*
Step 1
80.5%
2.544
Step 2
Adult lexical logfrequency value
Note. R2 = .756 for Step 1; Δ R2 = .114 for Step 2.
*p < .05. **p < .005.
DISCUSSION
Figure 1. Overall Past Tense Marking by Lexical Aspect Category
100
90
80
70
60
50
40
30
Retrospective analysis of findings from a prior study of elicited past
tense productions of preschoolers with variable tense marking
(Weiler & Schuele, 2011) using multiple linear regression analysis
showed that stem-final phonology significantly predicted variance
associated with percent correct past tense marking for verbs within
both lexical aspect categories. Consistent with prior studies (e.g.,
Marchman, Wulfeck, & Ellis Weismer, 1999), all verbs, regardless of
lexical aspect, with alveolar stop consonant stem endings were less
likely to be marked for past tense. Such verbs may be more
susceptible to omissions of past tense markers since there are bare
stem verbs ending in alveolar stop consonants that are legitimately
zero-marked for past tense (e.g.. hit, bid, cut).
20
After accounting for stem-final phonology, only variance in
Accomplishment past tense accuracies was predictable from adult
lexical log-frequency values. This finding should be interpreted
cautiously given that it was powered at .56 (alpha = .05).
Comparable partial R2 values over a corpus of fifteen verbs, five
more than the present analysis, would reach power at .80.
10
0
Achievement
Accomplishment
Figure 2. Percent Past Tense Variance Explained by Predictors
**
**
Results of this study suggest differential adult input influences on
past tense development relative to lexical aspect category. If, as
Brown and others observed, early-emerging past tense use is
primarily restricted to Achievements, then past tense marking for
Accomplishments may be more dependent on adult input as
children begin to more flexibly apply past-tense morphology to less
prototypical contexts (Olsen & Weinberg, 1999).
ACKNOWLEDGEMENTS
Data collection was supported by NIH/NIDCD (PI: Schuele). Completion of this study and preparation of
this poster were supported by a Preparation of Leadership Personnel grant (H325D080075; PI: Schuele),
U.S. Department of Education.
LIST OF CITED REFERENCES AVAILABLE ON REQUEST
http://www.mc.vanderbilt.edu/languagelab
Poster Presented at the Symposium on Research in Child Language Disorders, Madison, WI
June 2012
*p < .05. **p < .005
Irregular bare stem over-marked
1.833
Percent
Marked
eat*
write*
Task: The TEGI past tense probe is comprised of picture sets used to
elicit regular and irregular past tense verbs. For each item, an
examiner showed the child two pictures, one of an action in progress
and the other of the same action completed. The examiner described
the first picture using the target verb in a present progressive context
(e.g., Here the boy is cleaning her room.). Then, the child was asked
to describe the second, completed action picture using the prompt,
Now he/she is done. Tell me what he/she did. The child was prompted
to respond with a complete sentence, including a subject.
Scoring: For the purposes of the initial study, only those responses
containing the target verb in an obligatory context for past tense were
coded for analysis (see Table 4). Correctly marked regular and
irregular verbs were given credit. Verbs taking irregular past tense
forms (e.g., blow) that were marked with regular past tense
overgeneralizations of either the bare stem (e.g., blowed) or the past
tense form itself (e.g., blewed) also were given credit. Kuczaj (1977)
found that such past tense overgeneralization errors are produced by
children who have already demonstrated stable control of the regular
past tense rule. Responses containing the bare stem of the target verb
in an obligatory context for past tense (e.g., She clean her room.) were
not given credit. Interscorer reliability on past tense marking for
approximately one quarter of the scored responses was 90%.
Percent
Marked
Percent Marked for Past Tense
kick, jump, catch, blow, lift, give
Inflected
Accomplishment
Adult
Frequency
* = alveolar bare stem verb
Percent Variance Accounted for by Predictors
A comparison of past tense marking for Achievements versus
Accomplishments in an elicitation probe among typical preschoolers
(n = 52) who had not mastered past tense morphology revealed no
difference in omissions where inflected forms were obligatory (χ2(1)
= .156, p > .50; Weiler & Schuele, 2011). This finding suggests that
the instantaneous temporal property of Achievements implicated in
facilitating early-emerging past tense productions is not facilitative
of later preschool-aged past tense.
Accomplishment
Inflected
Adult
Frequency
Achievement
Table 3. VERB TARGETS BY CATEGORY
Achievement
Stem final phonology
Step 1
Table 5. Verb Properties and Accuracies by Lexical Aspect Type
Table 2. PARTICIPANT CHARACTERISTICS
Mean
SE B
Step 2
*
Prior work (e.g., Brown,1973; Bloom, Lifter, and Hafitz,1980; Shirai
and Anderson,1995) indicates that early emerging spontaneous
past tense productions frequently occur with Achievements. This is
speculated to be due to the prototypical way in which verbs
describing Achievements characterize visible events completed
rather instantly. Within a lexical aspect categorical framework, such
events, characterized by their defined endpoints and sudden
durations, are labeled Achievements. Accomplishments, on the
other hand, have defined endpoints but gradual durations (see
Table 1).
β
B