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Purpose: The aim of the current study was to investigate whether dual language experience modulates processing speed in typically developing (TD) children and in children with developmental language disorder (DLD). We also examined whether processing speed predicted vocabulary and sentence-level abilities in receptive and expressive modalities. Method: We examined processing speed in monolingual and bilingual school-age children (ages 8--12 years) with and without DLD. TD children (35 monolinguals, 24 bilinguals) and children with DLD (17 monolinguals, 10 bilinguals) completed a visual choice reaction time task. The Clinical Evaluation of Language Fundamentals, the Peabody Picture Vocabulary Test, and the Expressive Vocabulary Test were used as language measures. Results: The children with DLD exhibited slower response times relative to TD children. Response time was not modified by bilingual experience, neither in children with typical development nor children with DLD. Also, we found that faster processing speed was related to higher language abilities, but this relationship was not significant when socioeconomic status was controlled for. The magnitude of the association did not differ between the monolingual and bilingual groups across the language measures. Conclusions: Slower processing speed is related to lower language abilities in children. Processing speed is minimally influenced by dual language experience, at least within this age range.

Purpose: The aim of the current study was to investigate whether dual language experience modulates the efficiency of the 3 attentional networks (alerting, orienting, and executive control) in typically developing (TD) children and in children with developmental language disorder (DLD). Method: We examined the attentional networks in monolingual and bilingual school-aged children (ages 8-12 years) with and without DLD. TD children (35 monolinguals, 23 bilinguals) and children with DLD (17 monolinguals, 9 bilinguals) completed the Attention Network Test (Fan et al., 2002; Fan, McCandliss, Fossella, Flombaum, & Posner, 2005). Results: Children with DLD exhibited poorer executive control than TD children, but executive control was not modified by bilingual experience. The bilingual group with DLD and both TD groups exhibited an orienting effect, but the monolingual group with DLD did not. No group differences were found for alerting. Conclusions: Children with DLD have weak executive control skills. These skills are minimally influenced by dual language experience, at least in this age range. A potential bilingual advantage in orienting may be present in the DLD group.

Purpose: The aim of the current study was to investigate whether dual language experience modulates processing speed in typically developing (TD) children and in children with developmental language disorder (DLD). We also examined whether processing speed predicted vocabulary and sentence-level abilities in receptive and expressive modalities. Method: We examined processing speed in monolingual and bilingual school-age children (ages 8-12 years) with and without DLD. TD children (35 monolinguals, 24 bilinguals) and children with DLD (17 monolinguals, 10 bilinguals) completed a visual choice reaction time task. The Clinical Evaluation of Language Fundamentals, the Peabody Picture Vocabulary Test, and the Expressive Vocabulary Test were used as language measures. Results: The children with DLD exhibited slower response times relative to TD children. Response time was not modified by bilingual experience, neither in children with typical development nor children with DLD. Also, we found that faster processing speed was related to higher language abilities, but this relationship was not significant when socioeconomic status was controlled for. The magnitude of the association did not differ between the monolingual and bilingual groups across the language measures. Conclusions: Slower processing speed is related to lower language abilities in children. Processing speed is minimally influenced by dual language experience, at least within this age range. Supplemental Material: https://doi.org/10.23641/asha. 12210311, The purpose of this study is to examine whether processing speed differs between typically developing (TD) children and children with developmental language disorder (DLD), and if so, whether the group [...]

Purpose: The aim of the current study was to investigate whether dual language experience modulates the efficiency of the 3 attentional networks (alerting, orienting, and executive control) in typically developing (TD) children and in children with developmental language disorder (DLD). Method: We examined the attentional networks in monolingual and bilingual school-aged children (ages 812 years) with and without DLD. TD children (35 monolinguals, 23 bilinguals) and children with DLD (17 monolinguals, 9 bilinguals) completed the Attention Network Test (Fan et al., 2002; Fan, McCandliss, Fossella, Flombaum, & Posner, 2005). Results: Children with DLD exhibited poorer executive control than TD children, but executive control was not modified by bilingual experience. The bilingual group with DLD and both TD groups exhibited an orienting effect, but the monolingual group with DLD did not. No group differences were found for alerting. Conclusions: Children with DLD have weak executive control skills. These skills are minimally influenced by dual language experience, at least in this age range. A potential bilingual advantage in orienting may be present in the DLD group., Developmental language disorder (hereafter DLD; or specific language impairment) is a neurodevelopmental disorder whose primary clinical presentation is language difficulties without known causes, such as hearing impairment, intellectual disability, and [...]

Purpose: The aim of this study was to investigate whether dual language experience affects procedural learning ability in typically developing children and in children with specific language impairment (SLI). Method: We examined procedural learning in monolingual and bilingual school-aged children (ages 8-12 years) with and without SLI. The typically developing children (35 monolinguals, 24 bilinguals) and the children with SLI (17 monolinguals, 10 bilinguals) completed a serial reaction time task. Results: The typically developing monolinguals and bilinguals exhibited equivalent sequential learning effects, but neither group with SLI exhibited learning of sequential patterns on the serial reaction time task. Conclusion: Procedural learning does not appear to be modified by language experience, supporting the notion that it is a child-intrinsic language learning mechanism that is minimally malleable to experience.

Purpose: We asked whether sentence repetition accuracy could be explained by interactions of participant processing limitations with the structures of the sentences. We also tested a prediction of the procedural deficit hypothesis (Ullman & Pierpont, 2005) that adjuncts are more difficult than arguments for individuals with developmental language impairment (DLI). Method: Forty-four young adults participated, 21 with DLI. The sentence repetition task varied sentence length and the use of arguments and adjuncts. We also administered measures of working memory and processing speed. Our regression models focused on these interactions: group and argument status; processing speed, length, and argument status; and working memory capacity, length, and argument status. Results: Language ability group was a significant predictor of sentence repetition accuracy but did not interact with argument status. Processing speed interacted with sentence length and argument status. Working memory capacity and its separate interactions with argument status and sentence length predicted sentence repetition accuracy. Conclusions: Many adults with DLI may have difficulty with adjuncts as a result of their working memory limitations rather than their language ability. Cognitive limitations common to individuals with DLI are revealed more by particular sentence structures, suggesting ways to construct more diagnostically accurate sentence repetition tasks.

Purpose: The aim of this study was to investigate whether dual language experience affects procedural learning ability in typically developing children and in children with specific language impairment (SLI). Method: We examined procedural learning in monolingual and bilingual school-aged children (ages 8-12 years) with and without SLI. The typically developing children (35 monolinguals, 24 bilinguals) and the children with SLI (17 monolinguals, 10 bilinguals) completed a serial reaction time task. Results: The typically developing monolinguals and bilinguals exhibited equivalent sequential learning effects, but neither group with SLI exhibited learning of sequential patterns on the serial reaction time task. Conclusion: Procedural learning does not appear to be modified by language experience, supporting the notion that it is a child-intrinsic language learning mechanism that is minimally malleable to experience., People with specific language impairment (SLI), or primary language impairment as it is also known, have language difficulties in the absence of a known cause, such as intellectual disabilities, frank [...]

Purpose: This study investigated the relative utility of linguistic and nonlinguistic processing speed tasks as predictors of language impairment (LI) in children across 2 time points. Method: Linguistic and nonlinguistic reaction time data, obtained from 131 children (89 children with typical development [TD] and 42 children with LI; 74 boys and 57 girls) were analyzed in the 3rd and 8th grades. Receiver operating characteristic curve analyses and likelihood ratios were used to compare the diagnostic usefulness of each task. A binary logistic regression was used to test whether combined measures enhanced diagnostic accuracy. Results: In 3rd grade, a linguistic task, grammaticality judgment, provided the best discrimination between LI and TD groups. In 8th grade, a combination of linguistic and nonlinguistic tasks, rhyme judgment and simple response time, provided the best discrimination between groups. Conclusions: Processing speed tasks were moderately predictive of LI status at both time points. Better LR+ than LR- values suggested that slow processing speed was more predictive of the presence than the absence of LI. A nonlinguistic processing measure contributed to the prediction of LI only at 8th grade, consistent with the view that nonlinguistic and linguistic processing speeds follow different developmental trajectories.

Purpose: We asked whether sentence repetition accuracy could be explained by interactions of participant processing limitations with the structures of the sentences. We also tested a prediction of the procedural deficit hypothesis (Ullman & Pierpont, 2005) that adjuncts are more difficult than arguments for individuals with developmental language impairment (DLI). Method: Forty-four young adults participated, 21 with DLI. The sentence repetition task varied sentence length and the use of arguments and adjuncts. We also administered measures of working memory and processing speed. Our regression models focused on these interactions: group and argument status; processing speed, length, and argument status; and working memory capacity, length, and argument status. Results: Language ability group was a significant predictor of sentence repetition accuracy but did not interact with argument status. Processing speed interacted with sentence length and argument status. Working memory capacity and its separate interactions with argument status and sentence length predicted sentence repetition accuracy. Conclusions: Many adults with DLI may have difficulty with adjuncts as a result of their working memory limitations rather than their language ability. Cognitive limitations common to individuals with DLI are revealed more by particular sentence structures, suggesting ways to construct more diagnostically accurate sentence repetition tasks., Sentence repetition is a widely used task for the assessment of developmental language impairment (DLI) as part of standardized tests (Hammill & Newcomer, 1997; Semel, Wiig, & Secord, 2003). Researchers [...]

Purpose: To investigate the usefulness of 3 tasks known to be effective diagnostic clinical markers of specific language impairment (SLI) in children: (a) nonword repetition, (b) sentence repetition, and (c) grammaticality judgments of finiteness marking. Method: Two groups of young adults, 13 with SLI and 18 with typical language, completed 3 experimental tasks: (a) nonword repetition, (b) sentence repetition, and (c) grammaticality judgments of sentences that were either correct or contained an omitted finiteness marker, an overt agreement error, or an omitted progressive -"ing." Analyses included receiver operating characteristic curve analyses and computation of likelihood ratios associated with the use of each task as a clinical marker for SLI, as well as development of a logistic regression model that used multiple tasks as predictors. Results: Each marker task significantly contributed to classification of adults as affected or unaffected by SLI, with moderate positive and negative likelihood ratios. A combination of the 3 marker tasks was the best predictor of affectedness status with moderate to large likelihood ratios. Conclusions: The results suggest that SLI persists into adulthood and that effective clinical markers of this disorder are similar to those used to identify SLI in children. Refinement of these tasks to increase their likelihood ratios will improve their usefulness in diagnosing SLI in adults.

Purpose: Children with language impairment (LI) often perform below the level of typically developing peers on measures of both processing speed and working memory. This study examined the relationship between these 2 types of measures and attempted to determine whether such measures can account for the LI itself. Method: Fourteen-year-old children with LI and their typically developing peers participated in a wide range of processing speed and working memory tasks and were administered a comprehensive language test battery. Confirmatory factor analyses were used to compare 3 nested models designed to examine the dimensionality of the speed and working memory measures. A model that included a general speed factor was also evaluated. Results: The models meeting our evaluation criteria treated speed and working memory as separable factors. Furthermore, nonverbal as well as verbal processing factors emerged from these analyses. Latent variable regression analyses showed that each of the appropriate models accounted for 62% of the variance in the children's concurrent composite language test scores, with verbal working memory making the largest contribution. Conclusions: These findings shed light on the relationship among different types of processing and suggest that processing factors can contribute to the understanding of language disorders.

Purpose: To determine whether children with language impairment were slower than typically developing peers at age 14, and whether slowing, if present, was similar across task domains; whether differences in response time (RT) across domains were the same for children with specific language impairment (SLI) and nonspecific language impairment (NLI); and whether RT performance at age 9 predicted performance at age 14. Method: Fourteen-year-old children with SLI (n = 20), NLI (n = 15), and typical development (NLD; n = 31) were administered several linguistic and nonlinguistic speeded tasks. The children had received the same tasks at age 9. RT performance was examined. Results: Both the SLI and the NLI groups were significantly slower than the NLD group in motor, nonverbal cognitive, and language task domains, and there was no significant difference among domains. Individual analyses showed that most, but not all, children with SLI and NLI were slower than the NLD group mean. Slowing at age 9 and age 14 were moderately correlated. Conclusions: The results suggest that slow RT is a persistent characteristic of many children with language impairment; however, the nature of the relationship between RT and language performance requires further investigation.

Purpose: This study investigated the relative utility of linguistic and nonlinguistic processing speed tasks as predictors of language impairment (LI) in children across 2 time points. Method: Linguistic and nonlinguistic reaction time data, obtained from 131 children (89 children with typical development [TD] and 42 children with LI; 74 boys and 57 girls) were analyzed in the 3rd and 8th grades. Receiver operating characteristic curve analyses and likelihood ratios were used to compare the diagnostic usefulness of each task. A binary logistic regression was used to test whether combined measures enhanced diagnostic accuracy. Results: In 3rd grade, a linguistic task, grammaticality judgment, provided the best discrimination between Li and TD groups. In 8th grade, a combination of linguistic and nonlinguistic tasks, rhyme judgment and simple response time, provided the best discrimination between groups. Conclusions: Processing speed tasks were moderately predictive of LI status at both time points. Better LR+ than LR- values suggested that slow processing speed was more predictive of the presence than the absence of LI. A nonlinguistic processing measure contributed to the prediction of LI only at 8th grade, consistent with the view that nonlinguistic and linguistic processing speeds follow different developmental trajectories., This study investigated how linguistic and nonlinguistic processing speed tasks are related to the diagnosis of language impairment (LI) in children in middle childhood and early adolescence. The term specific [...]

Purpose: Decay of memory traces is an important component of many theories of working memory, but there is conflicting evidence on whether the rate of decay differs for individuals with specific language impairment (SLI) as compared to peers with typical language. The authors tested the hypothesis that adults with SLI have a slower decay rate. Method: Twenty adults with SLI, ages 18-27 years, and 23 age-matched peers identified target words in sentences. Sentences were presented at normal and slow rates. Participants separately judged whether a picture and sentence matched in meaning as a measure of sentence processing efficiency. Results: After controlling for sentence processing efficiency, the group with SLI was slower to detect words in sentences. Response times for the group with SLI increased less in the slow condition as compared to the group with typical language, resulting in a Group x Presentation Rate interaction. Conclusions: The Group x Presentation Rate interaction is consistent with a slower lexical decay rate for adults with SLI, but differences in the ability to manage interference could not be ruled out. The findings suggest that decay rate differences may play a role in the working memory limitations found in individuals with SLI., Individuals with specific language impairment (SLI) have unusually poor language abilities in the absence of hearing impairment, autism, cognitive impairment, or other clear causes (Leonard, 1998). Converging evidence indicates that [...]

Children with specific language impairment (SLI) show inconsistent use of grammatical morphology. Children who are developing language typically also show a period during which they produce grammatical morphemes inconsistently. Various theories claim that both young typically developing children and children with SLI achieve correct production through memorization of some inflected forms (M. Gopnik, 1997; M. Tomasello, 2000a, 2000b). Adapting a method introduced by C. Miller and L. Leonard (1998), the authors investigated the use of present tense third singular -s by 24 typically developing preschoolers and 36 preschoolers with SLI. Each group was divided into 2 mean length of utterance (MLU) levels. Group and individual data provided little evidence that memorization could explain the correct productions of the third singular morpheme for either children with SLI or typically developing children, and there was no difference between children with higher and lower MLUs.

This study examined difficulties in the use of -ed as passive participle or as past tense in 12 young children with specific language impairment. Results suggest that either the surface properties of -ed are related to the difficulty or these children have a separate, non-tense- related deficit in the area of verb morphology. (Contains references.) (DB)

Fourteen preschoolers with specific language impairment (SLI) and 12 younger controls were more likely to produce auxiliary "is" to describe target pictures when the preceding sentence contained auxiliary "are" than when it contained past tense. Use of "is" was least likely when the preceding sentence was nonfinite. (Contains references.) (CR)

Evaluation of the grammatical morphology used by 50 preschool children with specific language impairment as a function of their lexical diversity found their use of finite-verb morphology (based on number of different verbs used) and noun-related morphology lagged behind expectations in comparison to a group of normally developing preschoolers. (Author/DB)

Speech samples from 18 children (ages three to six years) with speech language impairment (SLI) were analyzed. Findings suggest that models of grammatical morphology which assume that correct production of finite verb forms is due to rote memorization, random retrieval of these forms, or indiscriminate affixation cannot be correct. (DB)

Purpose: To investigate the usefulness of 3 tasks known to be effective diagnostic clinical markers of specific language impairment (SLI) in children: (a) nonword repetition, (b) sentence repetition, and (c) grammaticality judgments of finiteness marking. Method: Two groups of young adults, 13 with SLI and 18 with typical language, completed 3 experimental tasks: (a) nonword repetition, (b) sentence repetition, and (c) grammaticality judgments of sentences that were either correct or contained an omitted finiteness marker, an overt agreement error, or an omitted progressive -ing. Analyses included receiver operating characteristic curve analyses and computation of likelihood ratios associated with the use of each task as a clinical marker for SLI, as well as development of a logistic regression model that used multiple tasks as predictors. Results: Each marker task significantly contributed to classification of adults as affected or unaffected by SLI, with moderate positive and negative likelihood ratios. A combination of the 3 marker tasks was the best predictor of affectedness status with moderate to large likelihood ratios. Conclusions: The results suggest that SLI persists into adulthood and that effective clinical markers of this disorder are similar to those used to identify SLI in children. Refinement of these tasks to increase their likelihood ratios will improve their usefulness in diagnosing SLI in adults. KEY WORDS: specific language impairment, adults, assessment procedures, An extensive body of research has focused on specific language impairment (SLI) in children, but few studies have documented the nature of the disorder in adulthood. SLI often goes untreated [...]

Purpose: Children with language impairment (LI) often perform below the level of typically developing peers on measures of both processing speed and working memory. This study examined the relationship between these 2 types of measures and attempted to determine whether such measures can account for the LI itself. Method: Fourteen-year-old children with LI and their typically developing peers participated in a wide range of processing speed and working memory tasks and were administered a comprehensive language test battery. Confirmatory factor analyses were used to compare 3 nested models designed to examine the dimensionality of the speed and working memory measures. A model that included a general speed factor was also evaluated. Results: The models meeting our evaluation criteria treated speed and working memory as separable factors. Furthermore, nonverbal as well as verbal processing factors emerged from these analyses. Latent variable regression analyses showed that each of the appropriate models accounted for 62% of the variance in the children's concurrent composite language test scores, with verbal working memory making the largest contribution. Conclusions: These findings shed light on the relationship among different types of processing and suggest that processing factors can contribute to the understanding of language disorders. KEY WORDS: memory, cognition, language disorders, The term language impairment (LI) is often applied to children exhibiting a significant deficit in language development without accompanying problems such as hearing impairment, neurological damage, or mental retardation. Because [...]

Purpose: To determine whether children with language impairment were slower than typically developing peers at age 14, and whether slowing, if present, was similar across task domains; whether differences in response time (RT) across domains were the same for children with specific language impairment (SLI) and nonspecific language impairment (NLI); and whether RT performance at age 9 predicted performance at age 14. Method: Fourteen-year-old children with SLI (n = 20), NLI (n = 15), and typical development (NLD; n = 31) were administered several linguistic and nonlinguistic speeded tasks. The children had received the same tasks at age 9. RT performance was examined. Results: Both the SLI and the NLI groups were significantly slower than the NLD group in motor, nonverbal cognitive, and language task domains, and there was no significant difference among domains. Individual analyses showed that most, but not all, children with SLI and NLI were slower than the NLD group mean. Slowing at age 9 and age 14 were moderately correlated. Conclusions: The results suggest that slow RT is a persistent characteristic of many children with language impairment; however, the nature of the relationship between RT and language performance requires further investigation. KEY WORDS: language functions and disorders, adolescents, experimental research, Children with specific language impairment (SLI) demonstrate language abilities significantly below what is expected for their age, but show no evidence of hearing impairment, frank neuropathology, autism spectrum disorders, or [...]

Children with specific language impairment (SLI) show inconsistent use of grammatical morphology. Children who are developing language typically also show a period during which they produce grammatical morphemes inconsistently. Various theories claim that both young typically developing children and children with SLI achieve correct production through memorization of some inflected forms (M. Gopnik, 1997; M. Tomasello, 2000a, 2000b). Adapting a method introduced by C. Miller and L. Leonard (1998), the authors investigated the use of present tense third singular -s by 24 typically developing preschoolers and 36 preschoolers with SLI. Each group was divided into 2 mean length of utterance (MLU) revels. Group and individual data provided little evidence that memorization could explain the correct productions of the third singular morpheme for either children with SLI or typically developing children, and there was no difference between children with higher and lower MLUs. KEY WORDS: language disorders, specific language impairment, grammatical morphology, productivity, English-speaking children with specific language impairment (SLI) frequently omit grammatical morphemes. This is a central feature of SLI and a focal point for many theories about its nature and causes. [...]

Children with specific language impairment (SLI) use past tense -ed in fewer obligatory contexts than younger normally developing children matched for mean length of utterance (MLU). In this study, the use of passive participle -ed (e.g., kissed in The frog got kissed by the kitty) as well as past tense -ed was examined in children with SLI, normally developing children matched for age (ND-A), and normally developing children matched for MLU (ND-MLU). The children with SLI used both past tense -ed and passive participle -ed. in fewer obligatory contexts than both the ND-A and the ND-MLU children. Only the children with SLI had greater difficulty with past tense -ed than with passive participle -ed. The pattern of findings indicates that the surface properties of -ed cannot adequately account for the past tense -ed difficulty shown by the children with SLI. However, the fact that the children with SLI were less consistent than the ND-MLU children in using passive participle -ed suggests that either the surface properties of -ed are responsible for a portion of the difficulty or these children have a separate, nontense-related deficit in the area of verb morphology. KEY WORDS: specific language impairment, grammatical morphology, grammar, past tense, participle, In recent years, there has been a great deal of evidence showing that English-speaking preschoolers with specific language impairment (SLI) have significant difficulties in using regular past tense. For example, [...]

Recent evidence from structural priming studies suggests that children with specific language impairment (SLI) are more likely to produce verb morphemes such as auxiliary is when their previous sentence contained an auxiliary than when it did not. The same paradigm was employed in the present study to determine whether failures to include auxiliary is might be due to prior use of nonfinite sentences (e.g., The mouse eating the cheese). Preschoolers with SLI and a group of younger normally developing children were more likely to produce auxiliary is to describe target pictures when the preceding sentence contained auxiliary are than when it contained past tense. Use of is in the target sentence was least likely when the preceding sentence was nonfinite. The implications of these findings far current accounts of SLI and current models of sentence production are discussed. KEY WORDS: specific language impairment, language disorders, language development, grammatical morphology, syntax, English-speaking children with specific language impairment (SLI) often produce verbs lacking tense and agreement information, even when the grammatical context calls for such information. Productions such as Mommy dancing for [...]

The grammatical morphology deficits common in children with specific language impairment (SLI) are characterized in some models as linguistic deficits. Such models must assume some mechanism for correct productions of finite verb forms. Three such assumptions were tested by analyzing speech samples from 18 children with SLI (aged 3 years 6 months to 6 years 9 months). Assumption 1, that nonfinite forms are used consistently until replaced by memorized finite forms, was tested by examining the distribution of verb types in present third-person singular and noun types in present third-person singular contractible copula contexts. Significantly more word types than expected were inflected inconsistently. Both Assumption 2, that finite and nonfinite verb forms are memorized but used indiscriminately, and Assumption 3, that affixation rules are applied indiscriminately, predict random use of finite forms. This prediction was not supported. KEY WORDS: specific language impairment, language disorders, grammatical morphology, language development

The aim of the present study was to investigate the speed with which children with specific language impairment (SLI) respond on a range of tasks. Seventy-seven third-grade children participated in 10 different tasks (involving a total of 41 conditions), including nonlinguistic and linguistic activities. Mean response times (RTs) of children with SLI (n = 29) increased as a function of mean RTs of children with normal language (NLD, n = 29) under each of three different regression models; children with SLI responded more slowly across all task conditions, and also when linguistic and nonlinguistic tasks were analyzed separately. Children with nonspecific language impairment (NLI) were also included (n = 19). The results were similar to those for children with SLI, but the degree of slowing was greater. The results of the group analyses support the hypothesis that speed of processing in children with SLI is generally slower than that of children with normal language. However, some children with SLI do not appear to show deficits of this type. KEY WORDS: specific language impairment, processing speed, response time, generalized slowing, school-age children, Children are usually identified by researchers as having a specific language impairment (SLI) when there are no obvious contributing factors, such as hearing impairment, neurological impairment, or mental retardation, that [...]

We examined the use of grammatical morphology by preschool-age English-speaking children with specific language impairment (SLI) as a function of their lexical diversity. Relative to a group of normally developing (ND) preschoolers, these children's use of finite-verb morphology lagged behind expectations based on the number of different verbs they used. Noun-related morphology fell below expectations based on overall lexical diversity. Differences between the ND children and children with SLI were also seen for the slope of the increases in finite-verb morphology as a function of lexical diversity, with shallower slopes in the SLI data. The findings of this study add to existing evidence suggesting that a measure of finite grammatical-morphology use has promise as a clinical marker of SLI in English. KEY WORDS: specific language impairment, grammatical morphology, lexicon, language disorders (in children), grammar