A further look at two grammatical measures from children's language samples and their contribution to the diagnostic process.

Previous research has identified two measures derived from language sample analysis as having a high level of diagnostic accuracy for developmental language disorder (DLD): a verb-based measure, the Finite Verb Morphology Composite (FVMC) and a more comprehensive grammatical measure, the Sentence Point. In this study, we evaluated the sensitivity and specificity of these two measures using a new group of children with DLD. To determine whether these measures would likely add to diagnostic decision making if used in conjuncion with other tests of language, we also examined the relationship between scores on these two measures and scores on a standardized test with a grammatical emphasis. In Study 1, FVMC and Sentence Point scores were computed from the language samples of 22 four- and five-year-olds with DLD and 22 age-matched typically developing peers. Both measures showed very good sensitivity and specificity. In Study 2, we analyzed the FVMC and the Sentence Point correlations with the SPELT-P2 for the 22 children wtih DLD from Study 1 and for a larger group of 60 children with DLD. All correlations were very low and non-significant. Results suggest that the FVMC and Sentence Point could be part of a diagnostic battery for DLD as these measures demonstrate good sensitivity and specificity. Furthermore, the findings of very low correlations between these measures and the SPELT-P2 suggest that they can contribute unique information to the diagnostic process even when used in concert with standardized tests of a grammatical nature.

Verb morphology in Turkish-speaking children with and without DLD: the role of morphophonology.

In this study, we examined the verb morphology system of Turkish-speaking preschoolers with developmental language disorder (DLD) and compared their use to that of two groups of typically developing (TD) children. We report data from a total of 80 monolingual children - 40 children with DLD, 20 TD age-matched children and 20 TD younger MLU-matched children. Language samples obtained from the children served as the source of the data. The results show that the children with DLD were less accurate in their use of verb suffixes than both the younger and the age-matched TD children. The most frequent error types included use of bare stems, omission of the suffix, and replacing one finite verb suffix with another. The distinction between witnessed past and reported past also posed a challenge. Multi-level model results showed that phonemic length and irregular morphophonology were the best predictors of the children's level of accuracy. These results indicate that even though Turkish is considered a "verb friendly" language, children with DLD do not succeed in closing the gap with their TD peers. The complex interplay of morphology and phonology in Turkish appears to be the major obstacle for children with DLD acquiring this agglutinative language.

Production of noun suffixes by Turkish-speaking children with developmental language disorder and their typically developing peers.

BACKGROUND: Turkish has a rich system of noun suffixes, and although its complex suffixation system may seem daunting, it can actually present a learning opportunity for children. Despite its unique features, Turkish has not been studied extensively, especially in the case of children with language deficits, such as developmental language disorder (DLD). Most of the extant studies are focused on bilingual children, and the results are somewhat mixed. AIMS: To focus on the noun morphology system of Turkish-speaking preschoolers with DLD and compare their use with that of two groups of typically developing (TD) children. Moreover, to investigate the nature of their noun suffix errors in detail. METHODS & PROCEDURES: We report data from a total of 80 monolingual children, 40 children with DLD (age range = 4;0-7;10), 20 TD age-matched children (4;0-7;3) and 20 younger mean length of utterance (MLU)-matched children (2;0-4;3). The data for this study came from language samples obtained from children in individual clinical assessment sessions. OUTCOMES & RESULTS: The children with DLD made less use of noun suffixes than both the younger and the age-matched TD children. The use of the unmarked (nominative case) form in place of an overt suffix was the most likely error by all groups. Suffix-change alternations required beyond vowel harmony seemed to pose real problems for these children. CONCLUSIONS & IMPLICATIONS: These results suggest that even when a language appears to provide significant advantages for the learning of noun morphology, children with DLD do not succeed in closing the gap. Certain factors such as morphophonological changes beyond vowel harmony, multiple allomorphs for the same suffix type and accusative suffixes that are not uniformly applied in the adult input were found to be significant predictors of the DLD group's difficulty with noun suffixes. Because these same factors can serve as characteristics of other languages, a child's difficulties might seem to be language specific (e.g., a particular allomorph in the language), but may actually be based on a broader difficulty (e.g., dealing with multiple allomorphs for the same suffix). Accordingly, factors that transcend a single language should be considered during clinical assessment and therapy. What this paper adds? What is already known on this subject? The current literature on the use of noun suffixes by Turkish-speaking children with DLD is very limited. Although Turkish is often described as a learner-friendly language, the degree to which children with DLD enjoy these learning benefits is unknown. What does this paper add to existing knowledge? Turkish children with DLD are less accurate in noun suffixes than both age-matched and younger control groups. For this group, the central problem seems to be increased complexity in morphophonology rather than difficulty with suffixation more generally. What are some of the clinical applications of this study? For clinicians who work with Turkish-speaking children with DLD, priority should be given to morphophonology. These children would benefit from treatment that focuses on how to attach different allomorphs to different open-class words. Because factors such as morphophonological complexity operate in other languages, the findings have broader clinical implications. In particular, regardless of the target language, clinicians should consider the possibility that these broader factors, rather than language-specific details, are the basis for a child's difficulty.

Five overarching factors central to grammatical learning and treatment in children with developmental language disorder.

BACKGROUND: During grammatical treatment of children with developmental language disorder (DLD), it is natural for therapists to focus on the grammatical details of the target language that give the children special difficulty. However, along with the language-specific features of the target (e.g., for English, add -s to verbs in present tense, third-person singular contexts), there are overarching factors that operate to render the children's learning task more, or less, challenging, depending on the particular target. AIMS: To identify five such factors that can play a role in the grammatical learning of children with DLD. We use English as our example language and provide supporting evidence from a variety of other languages. MAIN CONTRIBUTION: We show that the relative degree of English-speaking children's difficulty with particular grammatical details can be affected by the extent to which these details involve: (1) bare stems; (2) opportunities for grammatical case confusion; (3) prosodic challenges; (4) grammatical and lexical aspect; and (5) deviations from canonical word order. CONCLUSIONS: During treatment, therapists will want to consider not only the English-specific features of grammatical targets but also how these more general factors can be taken into account to increase the children's success.

Third person singular -s in typical development and specific language impairment: Input and neighbourhood density.

The purpose of this study was to examine factors promoting the use of third person singular -s by 23 children with specific language impairment (SLI) and 21 children with typical development (TD). Relative proportions of third person singular -s forms in the input (input proportion) were calculated for 25 verbs based on data from an American English corpus of child-directed speech. Neighbourhood density values were also collected for these verbs. With previously collected probes of third person singular -s use for each of these verbs, we found with logistic regression that input proportion was positively associated with the likelihood of third person singular -s use for both groups. For neighbourhood density, we found that children with SLI were more likely to inflect sparse verbs than dense verbs; density was not significantly related to inflection use for TD children. We argue that as a result of their verbs' poorly encoded phonological representations, children with SLI were less able to inflect dense verbs than sparse verbs. We recommend that clinicians be aware of the effects of input proportion and neighbourhood density to ensure that assessments are representative and that treatment success is optimal.

Case assignment in English-speaking children: a paired priming paradigm.

This study employed a paired priming paradigm to ask whether input features influence a child's propensity to use non-nominative versus nominative case in subject position, and to use non-nominative forms even when verbs are marked for agreement. Thirty English-speaking children (ages 2;6 to 3;7) heard sentences with pronouns that had non-contrasting case forms (e.g. Dad hugs it and it hugs Tigger) and it was hypothesized that these forms would lead to more errors (e.g. Him hugs Barney) in an elicited phrase more often than if the children heard contrasting case forms (e.g. Dad hugs us and we hug the doggie). Tense/agreement features were also examined in children's elicited productions. The findings were consistent with predictions, and supported the input ambiguity hypothesis of Pelham (2011). Implications for current accounts of the optional infinitive stage are discussed.

Input sources of third person singular -s inconsistency in children with and without specific language impairment.

We tested four predictions based on the assumption that optional infinitives can be attributed to properties of the input whereby children inappropriately extract non-finite subject-verb sequences (e.g., the girl run) from larger input utterances (e.g., Does the girl run? Let's watch the girl run). Thirty children with specific language impairment (SLI) and thirty typically developing children heard novel and familiar verbs that appeared exclusively either in utterances containing non-finite subject-verb sequences or in simple sentences with the verb inflected for third person singular -s. Subsequent testing showed strong input effects, especially for the SLI group. The results provide support for input-based factors as significant contributors not only to the optional infinitive period in typical development, but also to the especially protracted optional infinitive period seen in SLI.

Children with specific language impairment and their contribution to the study of language development.

Children with specific language impairment (SLI) are distinguishable from typically developing children primarily in the pace and course of their language development. For this reason, they are appropriate candidates for inclusion in any theory of language acquisition. In this paper, the areas of overlap between children with SLI and those developing in typical fashion are discussed, along with how the joint study of these two populations can enhance our understanding of the language development process. In particular, evidence from children with SLI can provide important information concerning the role of language typology in language development, the optimal ages for acquiring particular linguistic details, the robustness of the bilingual advantage for children, the role of input in children's acquisition of grammatical details, the unintended influence of processing demands during language assessment, the contributions of treatment designs to the study of typically developing children, and the study of individual differences in language development.

Identifying risk for specific language impairment with narrow and global measures of grammar.

In this study, we ask (1) whether measures of the developmental level of the tense/agreement morphemes used by children have diagnostic value, as has been found for tense/agreement consistency; and (2) whether global measures of accuracy can be applied to children four and five years of age. The spontaneous speech samples of 112 four- and five-year-olds with specific language impairment (SLI) or typical language were analyzed. Group differences were seen for the developmental level of the children's tense/agreement morpheme use, but diagnostic accuracy did not reach acceptable levels, in contrast to a measure of tense/agreement consistency applied to the same data. A global measure of grammatical accuracy was found to be useful, but more appropriate for screening children already viewed as at risk for language difficulties. These findings suggest that an extended period of tense/agreement inconsistency may be more central to SLI than alternative measures related to tense/agreement morphology.

The use of negative inflections by Finnish-speaking children with and without specific language impairment.

Children with specific language impairment (SLI) have difficulty expressing subject-verb agreement. However, in many languages, tense is fused with agreement, making it difficult to attribute the problem to agreement in particular. In Finnish, negative markers are function words that agree with the subject in person and number but do not express tense, providing an opportunity to assess the status of agreement in a more straightforward way. Fifteen Finnish-speaking preschoolers with SLI, 15 age controls and 15 younger controls responded to items requiring negative markers in first person singular and plural, and third person singular and plural. The children with SLI were less accurate than both typically developing groups. However, their problems were limited to particular person-number combinations. Furthermore, the children with SLI appeared to have difficulty selecting the form of the lexical verb that should accompany the negative marker, suggesting that agreement was not the sole difficulty.

Sources of Misinterpretation in the Input and Their Implications for Language Intervention With English-Speaking Children.

PURPOSE: In English and related languages, many preschool-age children with developmental language disorder (DLD) have difficulties using tense and agreement consistently. In this review article, we discuss two potential input-related sources of this difficulty and offer several possible strategies aimed at circumventing input obstacles. METHOD: We review a series of studies from English, supplemented by evidence from computational modeling and studies of other languages. Collectively, the studies show that instances of failures to express tense and agreement in DLD resemble portions of larger sentences in everyday input in which tense and agreement marking is appropriately absent. Furthermore, experimental studies show that children's use of tense and agreement can be swayed by manipulating details in fully grammatical input sentences. RESULTS: The available evidence points to two particular sources of input that may contribute to tense and agreement inconsistency. One source is the appearance of subject + nonfinite verb sequences that appear in auxiliary-fronted questions (e.g., Is [the girl running]? Does [the boy like popcorn]?) and as dependent clauses in more complex sentences (e.g., Help [her wash the dishes]; We saw [the frog hopping]). The other source is the frequent appearance of bare stems in the input, whether nonfinite (e.g., go in Make him go fast) or finite (e.g., go in I go, you go). CONCLUSIONS: Although the likely sources of input are a natural part of the language that all children hear, procedures that alter the distribution of this input might be used in the early stages of intervention. Subsequent steps can incorporate more explicit comprehension and production techniques. A variety of suggestions are offered.

Verb Vocabulary Supports Event Probability Use in Developmental Language Disorder.

PURPOSE: Children with developmental language disorder (DLD) tend to interpret noncanonical sentences like passives using event probability (EP) information regardless of structure (e.g., by interpreting "The dog was chased by the squirrel" as "The dog chased the squirrel"). Verbs are a major source of EP information in adults and children with typical development (TD), who know that "chase" implies an unequal relationship among participants. Individuals with DLD have poor verb knowledge and verb-based sentence processing. Yet, they also appear to rely more on EP information than their peers. This paradox raises two questions: (a) How do children with DLD use verb-based EP information alongside other information in online passive sentence interpretation? (b) How does verb vocabulary knowledge support EP information use? METHOD: We created novel EP biases by showing animations of agents with consistent action tendencies (e.g., clumsy vs. helpful actions). We then used eye tracking to examine how this EP information was used during online passive sentence processing. Participants were 4- to 5-year-old children with DLD (n = 20) and same-age peers with TD (n = 20). RESULTS: In Experiment 1, children with DLD quickly integrated verb-based EP information with morphosyntax close to the verb but failed to do so with distant morphosyntax. In Experiment 2, the quality of children's sentence-specific verb vocabulary knowledge was positively associated with the use of EP information in both groups. CONCLUSION: Depending on the morphosyntactic context, children with DLD and TD used EP information differently, but verb vocabulary knowledge aided its use. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.25491805.

Retrieval Practice and Word Learning by Children With Developmental Language Disorder: Does Expanding Retrieval Provide Additional Benefit?

PURPOSE: The word learning of preschool-age children with developmental language disorder (DLD) is improved when spaced retrieval practice is incorporated into the learning sessions. In this preregistered study, we compared two types of spacing-an expanding retrieval practice schedule and an equally spaced schedule-to determine if one of these approaches yields better word learning outcomes for the children. METHOD: Fourteen children with DLD aged 4-5 years and 14 same-age children with typical language development (TD) learned eight novel nouns over two sessions. Spacing for half of the novel words was expanded gradually during learning; for the remaining novel words, greater spacing remained at the same level throughout learning. Immediately after the second session and 1 week later, the children's recall of the words was tested. RESULTS: The children with TD recalled more novel words than the children with DLD, although this difference could be accounted for by differences in the children's standardized receptive vocabulary test scores. The two groups were similar in their ability to retain the words over 1 week. Initially, the shorter spacing in the expanding schedule resulted in greater retrieval success than the corresponding (longer spaced) retrieval trials in the equally spaced schedule. These early shorter spaced trials also seemed to benefit retrieval of the trials with greater spacing that immediately followed. However, as the learning period progressed, the accuracy levels for the two conditions converged and were likewise similar during final testing. CONCLUSION: We need a greater understanding of how and when short spacing can be helpful to children's word learning, with the recognition that early gains might give a misleading picture of the benefits that short spacing can provide to longer term retention. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.25537696.

Clinical markers in Italian-speaking children with and without specific language impairment: a study of non-word and real word repetition as predictors of grammatical ability.

BACKGROUND: In many languages a weakness in non-word repetition serves as a useful clinical marker of specific language impairment (SLI) in children. However, recent work in Italian has shown that the repetition of real words may also have clinical utility. For young typically developing Italian children, real word repetition is more predictive of particular grammatical abilities than is non-word repetition. This finding is important because these particular grammatical abilities--the production of present-tense third-person plural inflections and direct-object clitic pronouns--are precisely those that are problematic for Italian-speaking children with SLI. Along with their grammatical requirements, these two morpheme types present a significant phonological/prosodic challenge for these children. AIMS: To replicate the findings with young typically developing Italian children and to determine whether real word repetition is also more predictive of the use of these two morpheme types than is non-word repetition in a group of Italian-speaking children with SLI. METHODS & PROCEDURES: Seventeen Italian-speaking children with SLI and 17 younger typically developing children matched for mean length of utterance participated in tasks of real word and non-word repetition as well as tasks requiring the production of direct-object clitic pronouns and present-tense third-person plural inflections. OUTCOMES & RESULTS: Children with SLI were less accurate than their younger peers on all measures. Importantly, for the younger typically developing children, real word repetition explained a significant amount of variance in the use of third-person plural inflections and direct-object clitic pronouns. For the children with SLI, in contrast, non-word repetition was a significant predictor, whereas real word repetition was not a contributing factor. CONCLUSIONS & IMPLICATIONS: It is argued that in Italian SLI, the grammatical details showing the greatest weakness present phonological/prosodic obstacles as well as grammatical challenges to these children. Consequently, non-word repetition emerges as a predictor of these grammatical weaknesses in SLI, unlike the profile observed in typically developing Italian children.

Can Retrieval Practice Facilitate Verb Learning in Children With Developmental Language Disorder and Their Peers With Typical Language Development?

PURPOSE: Children with developmental language disorder (DLD) have well-documented verb learning difficulties. In this study, we asked whether the inclusion of retrieval practice during the learning period would facilitate these children's verb learning relative to a similar procedure that provided no retrieval opportunities. METHOD: Eleven children with DLD (M age = 60.09 months) and 12 children with typical language development (TD; M age = 59.92 months) learned four novel verbs in a repeated spaced retrieval (RSR) condition and four novel verbs in a repeated study (RS) condition. The words in the two conditions were heard an equal number of times, in the context of video-recorded actors performing novel actions. RESULTS: Recall testing immediately after the learning period and 1 week later revealed greater recall for novel verbs in the RSR condition than for novel verbs in the RS condition. This was true for both groups, and for immediate as well as 1-week testing. The RSR advantage remained when children had to recall the novel verbs while watching new actors perform the novel actions. However, when tested in contexts requiring the children to inflect the novel verbs with -ing for the first time, the children with DLD were much less likely to do so than their peers with TD. Even words in the RSR condition were only inconsistently inflected. CONCLUSIONS: Retrieval practice provides benefits to verb learning-an important finding given the challenges that verbs present to children with DLD. However, these benefits do not appear to automatically translate to the process of adding inflections to newly learned verbs but rather appear to be limited to the operations of learning the verbs' phonetic forms and mapping these forms onto associated actions.

A cross-linguistic study of real-word and non-word repetition as predictors of grammatical competence in children with typical language development.

BACKGROUND: Although relationships among non-word repetition, real-word repetition and grammatical ability have been documented, it is important to study whether the specific nature of these relationships is tied to the characteristics of a given language. AIMS: The aim of this study is to explore the potential cross-linguistic differences (Italian and English) in the relationship among non-word repetition, real-word repetition, and grammatical ability in three-and four-year-old children with typical language development. METHODS & PROCEDURES: To reach this goal, two repetition tasks (one real-word list and one non-word list for each language) were used. In Italian the grammatical categories were the third person plural inflection and the direct-object clitic pronouns, while in English they were the third person singular present tense inflection and the past tense in regular and irregular forms. OUTCOMES & RESULTS: A cross-linguistic comparison showed that in both Italian and English, non-word repetition was a significant predictor of grammatical ability. However, performance on real-word repetition explained children's grammatical ability in Italian but not in English. CONCLUSIONS & IMPLICATIONS: Abilities underlying non-word repetition performance (e.g., the processing and/or storage of phonological material) play an important role in the development of children's grammatical abilities in both languages. Lexical ability (indexed by real-word repetition) showed a close relationship to grammatical ability in Italian but not in English. Implications of the findings are discussed in terms of cross-linguistic differences, genetic research, clinical intervention and methodological issues.

Children with specific language impairment in Finnish: the use of tense and agreement inflections.

Children with specific language impairment (SLI) vary widely in their ability to use tense/agreement inflections depending on the type of language being acquired, a fact that current accounts of SLI have tried to explain. Finnish provides an important test case for these accounts because: (1) verbs in the first and second person permit null subjects whereas verbs in the third person do not; and (2) tense and agreement inflections are agglutinating and thus one type of inflection can appear without the other. Probes were used to compare the verb inflection use of Finnish-speaking children with SLI, and both age-matched and younger typically developing children. The children with SLI were less accurate, and the pattern of their errors did not match predictions based on current accounts of SLI. It appears that children with SLI have difficulty learning complex verb inflection paradigms apart from any problem specific to tense and agreement.

Input Distribution Influences Degree of Auxiliary Use by Children with Specific Language Impairment.

Children with specific language impairment (SLI) show a protracted period of inconsistent use of tense/agreement morphemes. The purpose of this investigation was to determine whether this inconsistent use could be attributed to the children's misinterpretations of particular syntactic structures in the input. In Study 1, preschool-aged children with SLI and typically developing peers heard sentences containing novel verbs preceded by auxiliary was or sentences in which the novel verb formed part of a nonfinite subject-verb sequence within a larger syntactic structure (e.g., We saw the dog relling). The children were then tested on their use of the novel verbs in contexts that obligated use of auxiliary is. The children with SLI were less accurate than their peers and more likely to produce the novel verb without is if the verb had been heard in a nonfinite subject-verb sequence. In Study 2, children with SLI and typically developing peers were tested on their comprehension of sentences such as The cow sees the horse eating. The children with SLI were less accurate than their peers and were disproportionately influenced by the nonfinite subject-verb clause at the end of the sentence. We interpret these findings within the framework of construction learning.

Moving towards accurate and early prediction of language delay with network science and machine learning approaches.

Due to wide variability of typical language development, it has been historically difficult to distinguish typical and delayed trajectories of early language growth. Improving our understanding of factors that signal language disorder and delay has the potential to improve the lives of the millions with developmental language disorder (DLD). We develop predictive models of low language (LL) outcomes by analyzing parental report measures of early language skill using machine learning and network science approaches. We harmonized two longitudinal datasets including demographic and standardized measures of early language skills (the MacArthur-Bates Communicative Developmental Inventories; MBCDI) as well as a later measure of LL. MBCDI data was used to calculate several graph-theoretic measures of lexico-semantic structure in toddlers' expressive vocabularies. We use machine-learning techniques to construct predictive models with these datasets to identify toddlers who will have later LL outcomes at preschool and school-age. This approach yielded robust and reliable predictions of later LL outcome with classification accuracies in single datasets exceeding 90%. Generalization performance between different datasets was modest due to differences in outcome ages and diagnostic measures. Grammatical and lexico-semantic measures ranked highly in predictive classification, highlighting promising avenues for early screening and delineating the roots of language disorders.

Simulating the Acquisition of Verb Inflection in Typically Developing Children and Children With Developmental Language Disorder in English and Spanish.

Children with developmental language disorder (DLD) have significant deficits in language ability that cannot be attributed to neurological damage, hearing impairment, or intellectual disability. The symptoms displayed by children with DLD differ across languages. In English, DLD is often marked by severe difficulties acquiring verb inflection. Such difficulties are less apparent in languages with rich verb morphology like Spanish and Italian. Here we show how these differential profiles can be understood in terms of an interaction between properties of the input language, and the child's ability to learn predictive relations between linguistic elements that are separated within a sentence. We apply a simple associative learning model to sequential English and Spanish stimuli and show how the model's ability to associate cues occurring earlier in time with later outcomes affects the acquisition of verb inflection in English more than in Spanish. We relate this to the high frequency of the English bare form (which acts as a default) and the English process of question formation, which means that (unlike in Spanish) bare forms frequently occur in third-person singular contexts. Finally, we hypothesize that the pro-drop nature of Spanish makes it easier to associate person and number cues with the verb inflection than in English. Since the factors that conspire to make English verb inflection particularly challenging for learners with weak sequential learning abilities are much reduced or absent in Spanish, this provides an explanation for why learning Spanish verb inflection is relatively unaffected in children with DLD.