Abstract
Keywords
Introduction
Two well-known neurodevelopmental disorders that affect language are developmental language disorder (DLD) and autism spectrum disorder (ASD). Both conditions impact academic, social, and emotional development, but differ in their primary characteristics: DLD involves persistent language difficulties without hearing, neurological, or motor deficits (Bishop, 2017; Bishop et al., 2016; Norbury et al., 2024), while ASD is defined by challenges in social communication and restricted or repetitive behaviors (American Psychiatric Association, 2022; Bottema-Beutel et al., 2021). Within ASD, there is substantial heterogeneity, with some children presenting with language impairments (ASD-LI) and others exhibiting language within the typical range (ASD-LN) (Grzadzinski et al., 2013; Kjelgaard & Tager-Flusberg, 2001; Lord & Jones, 2012; Roberts et al., 2004; Schaeffer et al., 2023).
Morphosyntactic Abilities in DLD and ASD
Children with DLD consistently demonstrate morphosyntactic difficulties, such as omission or simplification of morphemes, tense and agreement errors, and challenges with pluralization and pronoun use (Calder et al., 2022; Castilla-Earls et al., 2020; Güven & Leonard, 2023; Leonard, 2014; Moraleda-Sepúlveda & López-Resa, 2022; Restrepo & Gutierrez-Clellen, 2001; Rice & Wexler, 1996). These difficulties have been documented across languages: in English (Calder et al., 2021, 2023; Leonard, 2014; Rice & Wexler, 1996), Spanish (Castilla-Earls et al., 2020; Restrepo & Gutierrez-Clellen, 2001), Swedish (Reuterskiöld et al., 2021), Turkish (Güven & Leonard, 2023), and Arabic (Alharbi et al., 2025). This body of evidence suggests that morphosyntactic deficits may serve as a cross-linguistic clinical marker of DLD.
Similarly, children with ASD-LI often show comparable morphosyntactic difficulties, while ASD-LN generally perform closer to typically developing (TD) peers (Huang & Finestack, 2020; Kjelgaard & Tager-Flusberg, 2001; Roberts et al., 2004). For example, children with ASD-LI may omit tense marking, struggle with auxiliary and copular forms, and simplify complex syntactic structures (Bartolucci et al., 1980; Brynskov et al., 2017; Meir & Novogrodsky, 2020; Roberts et al., 2004; Sukenik & Friedmann, 2018; Tuller et al., 2017). Cross-linguistic research indicates that ASD-LI and DLD share some difficulties. In English, these include sentence repetition (Lloyd et al., 2006), receptive and expressive language abilities (Loucas et al., 2008), grammatical development in toddlers (Ellis Weismer et al., 2011), limited use of prepositional clauses, passive constructions, relative clauses, reflexive pronouns, Wh-clauses, and infinitives (Huang & Finestack, 2020). Similar patterns have also been observed in French, where both groups demonstrate comparable challenges in producing Wh-questions (Prévost et al., 2017). However, to the best of our knowledge, no study to date has directly compared the morphosyntactic abilities of children with DLD, ASD-LI, and ASD-LN in Semitic languages. This gap is particularly important, as Semitic languages are characterized by a root-and-pattern morphology and non-linear inflectional and derivational processes that pose challenges that differ from those of Indo-European languages. Addressing this gap in Hebrew therefore offers a unique opportunity to evaluate whether the similarities and differences reported for other languages extend to a typologically distinct system.
The Case of Hebrew
As a Semitic language, Hebrew has a rich morphological system, including root-and-pattern derivation (e.g., the root
Prior studies of Hebrew-speaking children with DLD aged 4 to 6 years have demonstrated significant challenges with verb inflections (Dromi et al., 1993, 1999; Leonard et al., 2000; Leonard & Dromi, 1994). Consistent with this, Hebrew-speaking children with ASD and co-occurring language impairment aged 4;6–9;2 years simplify complex syntactic structures and show difficulty with embedded clauses (Meir & Novogrodsky, 2020). Among adolescents aged 9;0–18;0 years, those with ASD and those with DLD perform comparably on syntactic tasks but exhibit different error patterns, suggesting distinct underlying mechanisms (Sukenik & Friedmann, 2018). However, despite these insights into morphology and syntax, no previous study has systematically examined both inflectional and derivational processes in nouns and verbs among Hebrew-speaking preschool children with DLD and ASD. Given that these skills may be linked to phonological memory, it is important to consider this domain as well.
Phonological Memory in Children With DLD and ASD
In their seminal study, Baddeley and Hitch (1974) proposed the working-memory model, which consists of a central control system, the central executive component—responsible for managing attention—and two supporting subsystems, namely, the phonological loop, which stores verbal and phonological information, and the visuospatial sketchpad, which stores visual and spatial information. Phonological memory refers to the ability to temporarily store and recall the phonological (sound-based) aspects of language, such as words or syllables. Difficulties with phonological memory are considered a core factor contributing to challenges in language acquisition (Baddeley, 2003; Gathercole, 2006).
The capacity of the phonological loop is most accurately assessed by storage of verbal information, that is, forward digit span, word and non-word repetition (NWR) (Barrouillet et al., 2007). Unlike forward digit span and word repetition, NWR and pseudoword repetition does not involve retrieving familiar words from long-term memory, which could support storage in the phonological loop (Hulme et al., 1991). NWR is considered an important clinical marker for DLD across different languages, including English (e.g., Bishop et al., 1996), Cantonese (Fu et al., 2024), Italian (Bortolini et al., 2006; Dispaldro et al., 2013), and Swedish (Kalnak et al., 2014). NWR effectively distinguishes children with DLD from TD peers (Kalnak et al., 2014; Poll et al., 2010).
Previous studies have suggested that phonological memory plays a crucial role in the language acquisition of children with DLD and is closely linked to grammar acquisition (Delage & Frauenfelder, 2020; Delcenserie et al., 2021; Dispaldro et al., 2013; Torrens & Yagüe, 2018). However, less is known about phonological memory in children with ASD-LI. Some studies indicate that children with ASD-LI exhibit reduced NWR performance, similar to findings in children with DLD (Abd El-Raziq et al., 2025; Jokel et al., 2021; Kjelgaard & Tager-Flusberg, 2001; Roberts et al., 2004). This suggests a possible shared impairment for ASD-LI and DLD. For instance, one study comparing children with ASD-LI, DLD, and TD peers on an NWR task found that children with ASD-LI performed similarly to those with DLD, differing from both ASD children without language impairment and TD controls (Tager-Flusberg, 2015). These findings support the idea that a subgroup of children with ASD also has DLD (Harper-Hill et al., 2013; Tager-Flusberg, 2015).
In contrast, other studies challenge this hypothesis, reporting that children with ASD-LI outperform those with DLD on NWR tasks, particularly in multisyllabic words. These findings suggest that phonological memory deficits may be more pronounced in DLD than in ASD-LI (Riches et al., 2011; Whitehouse et al., 2008; Williams et al., 2013). Given these mixed findings, further research is needed. In Hebrew-speaking children with DLD, the role of NWR remains underexplored. Investigating NWR in Hebrew-speaking children with DLD and ASD-LI and the association with morphosyntactic abilities could provide valuable insights into the nature of language impairment in these populations, contributing to a deeper understanding of cross-linguistic diagnostic markers.
The Present Study
The aims of the current study are to assess morphosyntactic characteristics and phonological memory across the following four groups: children with DLD, children with ASD with language impairment (ASD-LI), children with ASD with normal language development (ASD-LN), and TD children. By comparing these groups, we aim to determine whether deficits in these domains are shared across clinical categories or are specific to certain populations, thus contributing to a more precise characterization of language impairment in ASD and DLD.
An additional key objective of this study is to investigate the extent to which phonological memory is associated with morphosyntactic performance in each group. Given that phonological memory is known to support language acquisition, we hypothesize that children with weaker phonological memory skills will struggle more with morphosyntactic tasks. However, differences between groups may reveal distinct underlying impairment mechanisms. For instance, if phonological memory is related to morphosyntactic performance in both DLD and ASD-LI, this would suggest a shared cognitive basis for their language deficits. Conversely, if ASD-LI exhibits a pattern that differs from that of DLD, this may indicate that language difficulties in ASD arise from broader neurodevelopmental differences rather than limitations in phonological memory.
We hypothesized that (a) children with DLD and ASD-LI would demonstrate reduced morphosyntactic abilities compared to TD children and children with ASD-LN, (b) children with DLD and ASD-LI would demonstrate reduced phonological memory compared to TD children and children with ASD-LN, and (c) phonological memory would be positively correlated with morphosyntactic abilities across all groups, with weaker phonological memory predicting greater difficulties in morphosyntax. We predicted that this relationship would be strongest in the DLD and ASD-LI groups, suggesting a shared cognitive basis for language deficits in these populations.
Importantly, although morphosyntactic and phonological memory deficits in DLD and ASD-LI have been reported for other languages, the present study offers a novel empirical and theoretical contribution in several ways. First, it is the first systematic comparison of morphosyntactic abilities and phonological memory across DLD, ASD-LI, ASD-LN, and TD groups in Hebrew, a morphologically complex Semitic language. Second, by examining both inflectional morphology (morphosyntactic) and derivational morphology (lexical), the study captures a broader range of linguistic vulnerabilities than has been addressed in most prior work. Finally, by linking phonological memory performance to morphosyntactic outcomes, the study provides new evidence on the cognitive aspects related to morphosyntactic difficulties as well as supporting cross-linguistic diagnostic markers for distinguishing subgroups of children with neurodevelopmental disorders.
Method
Participants
This study included 80 monolingual Hebrew-speaking children (ages 63.6–72 months), divided into four groups of 20: ASD-LN, ASD-LI, DLD, and TD children as shown in Table 1. Gender distribution was comparable across groups (χ2(3) = 5.27,
Participants’ Characteristics.
Participants with ASD and DLD were recruited through special education programs and referrals by speech-language pathologists (SLPs) upon obtaining parental consent. ASD diagnoses were confirmed by psychiatric specialists using DSM-5 criteria (American Psychiatric Association, 2022). DLD diagnoses were established jointly by a pediatrician and a licensed SLP following standard clinical guidelines. As part of the diagnostic process, all children in the DLD group underwent evaluations to rule out ASD, ensuring that the DLD group did not include children with ASD. All children had normal vision, hearing, and nonverbal intelligence, and no history of neurological difficulties, as reported by parents. In addition, children's articulation was typical of their age according to their SLPs and the only speech impairment observed by the clinicians was related to sigmatism. TD children were recruited by means of social media advertisements targeted at SLPs and the public and word-of-mouth referrals. The TD children were verified to be free of neurodevelopmental issues through parental reports obtained via a developmental questionnaire, language assessments, and non-verbal intelligence tests.
Following recruitment, the children referred underwent a comprehensive reassessment involving two one-hour sessions. The first session focused on clinical diagnostic procedures, while standardized background tests were administered in the second session, providing detailed nonverbal intelligence and language ability data. This research was approved by Tel Aviv University's Research Ethics Committee (No. 0006493-2) and adhered to the Declaration of Helsinki. Parental consent was obtained for all participants.
Clinical Diagnostic Procedure
Test Materials and Procedure
Background Tests
Data Analysis
All analyses were performed using the Statistical Package for the Social Sciences (SPSS) version 29. The variables of the Goralnik, KHLA, and the Shatil memory subtests for syllable span and pseudoword repetition were normally distributed with Z-scores of skewness and kurtosis values between −2.58 and 2.58 for the four groups. The Raven scores were not normally distributed; therefore, Spearman's correlations were calculated between Raven and the other variables. Significant correlations were found between Raven and KHLA (
An independent samples Kruskal-Wallis test was performed on the Raven scores across groups. A one-way analysis of variance (ANOVA) was conducted on language scores (Goralnik) across groups. A one-way ANCOVA was performed to assess the differences between the groups in the KHLA. A one-way MANCOVA was performed to examine the differences between groups in the subtests of the KHLA and memory tasks, with the Raven standard scores as a covariate. The following pairwise comparisons were adjusted using the Bonferroni correction (
Results
Background Measures
A summary of nonverbal intelligence, and language abilities of children with ASD-LN, ASD-LI, DLD, and TD is presented in Table 2.
Descriptive Statistics of Participant Age, RAVEN's Progressive Matrices Scores, and Goralnik Language Scores.
An independent samples Kruskal-Wallis test was performed on the RAVEN scores.
A one-way analysis of variance (ANOVA) was conducted on the Goralnik scores.
Test Results
KHLA
The mean scores of the KHLA-adjusted and unadjusted for nonverbal intelligence are presented in Table 3. The highest unadjusted scores were found for the TD group (
Summary of Test Results. Mean and Standard Deviation for the KHLA Grammar Test and Subtests are Presented for Each Group, As Well As Adjusted Means and Standard Errors for Non-verbal Intelligence (RAVEN).
A one-way ANCOVA was conducted to examine the effect of group on KHLA while controlling for nonverbal intelligence (Raven standard scores). The analysis revealed a statistically significant group effect,
The mean scores for the six KHLA tasks across participant groups are shown in Table 3. A one-way MANCOVA was performed to examine group differences, revealing a significant main effect in the simultaneous test, Wilks’ λ = 0.56,
In Task 3 (plural inflection), TD children scored significantly higher than the ASD-LI group (
Shatil
The mean scores for the Shatil subtests, including pseudoword repetition and syllable span, both adjusted and unadjusted for nonverbal intelligence, are presented in Table 4. For non-word repetition, the TD group achieved the highest unadjusted mean score (
Summary of Test Results. Mean and Standard Deviation for the Shatil Pseudoword Repetition and Syllable Span Subtests are Presented for Each Group, As Well As Adjusted Means and Standard Errors for Non-verbal Intelligence (RAVEN).
Adjusted for RAVEN.
A one-way MANCOVA was performed to examine group differences while controlling for nonverbal intelligence (Raven standard scores), revealing a significant main effect in the simultaneous test, Wilks’ λ = 0.69,
Associations Between Shatil and KHLA
In order to examine the associations between phonological memory and morphosyntactic skills, we looked for correlations between the Shatil memory subtests for pseudoword repetition, syllable span, and the KHLA for each group as summarized in Figures 1 and 2.

Associations between Pseudoword Repetition and KHLA Morphosyntax test.

Associations between Syllable Span and KHLA Morphosyntax test.
The results demonstrated medium to strong correlations only in the groups of DLD (
Hierarchical Regression Analysis
A hierarchical multiple regression model was applied to the sample of the four groups of participants. The hierarchical model was run to determine whether adding the pseudoword repetition and syllable span improved the prediction of KHLA beyond nonverbal intelligence (Raven) and language abilities (the Goralnik test). The results are summarized in Table 5.
Regression Analysis for Predicting KHLA Performance Standardized for RAVEN.
Standardized for RAVEN.
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In Model 1, overall language scores on the Goralnik test significantly predicted morphosyntactic scores of the KHLA (
In Model 2, the addition of pseudoword repetition and syllable span significantly improved the model's explanatory power. While language scores remained a significant predictor (
The inclusion of pseudoword repetition and syllable span led to a statistically significant increase in explained variance (ΔR2 = .11, ΔF = 11.77,
These findings suggest that while language abilities remain the strongest predictor of morphosyntactic performance on the KHLA, phonological memory, provides additional explanatory power. The results highlight the significance of phonological processing skills in language development and suggest that deficits in phonological memory may contribute to lower morphosyntactic scores. Importantly, these effects were found after controlling for nonverbal cognitive abilities, confirming that the observed associations between language, phonological memory, and KHLA are not merely a reflection of broader cognitive factors.
Discussion
The present study investigated morphosyntactic abilities and phonological memory in four groups of Hebrew-speaking preschoolers: children with DLD, children with ASD-LI, children with ASD-LN, and TD peers. Our objectives were to compare these groups to clarify whether deficits are shared across conditions or are group-specific, and to determine the extent to which phonological memory contributes to morphosyntactic performance.
Morphosyntactic Abilities
In line with our first hypothesis, both the DLD and ASD-LI groups demonstrated reduced morphosyntactic abilities compared to TD children, while the ASD-LN group performed closer to TD peers. Children with ASD-LI did not differ significantly from children with DLD, but they scored significantly lower than those with ASD-LN. This pattern is consistent with earlier work showing that morphosyntactic abilities in ASD-LI resemble those of DLD (Huang & Finestack, 2020; Kjelgaard & Tager-Flusberg, 2001).
The analysis of KHLA subtests revealed that children with ASD-LI and DLD encountered difficulties across multiple domains, including verb inflection and derivation, plural inflection, and noun morphology, particularly irregular forms, as well as noun–adjective agreement and the derivation of consequential adjectives from verbs. These findings extend prior research showing that children with ASD-LI struggle with various aspects of morphosyntax (Alhassan & Marinis, 2023; Durrleman & Delage, 2016; Meir & Novogrodsky, 2023; Modyanova et al., 2017; Riches et al., 2011). Importantly, this is the first study to systematically compare Hebrew-speaking children with ASD-LN, ASD-LI, and DLD on both inflectional and derivational morphology.
Phonological Memory
Consistent with our second hypothesis, children with ASD-LI and DLD showed reduced raw scores on both pseudoword repetition and syllable repetition relative to their TD peers. These findings align with prior work linking phonological memory weaknesses to language difficulties in both DLD and ASD-LI (Delcenserie et al., 2021; Dispaldro et al., 2013; Jokel et al., 2021; Kjelgaard & Tager-Flusberg, 2001; Tager-Flusberg, 2015). Importantly, when nonverbal intelligence (Raven scores) was included as a covariate, group differences in pseudoword repetition were no longer statistically significant. This suggests that performance on the pseudoword task may rely partly on general cognitive ability rather than reflecting a strictly language-specific deficit. In contrast, significant group differences in syllable span persisted after controlling for Raven, indicating that limitations in phonological memory represent a robust, domain-specific vulnerability in ASD-LI and DLD. Notably, even the ASD-LN group performed below TD peers on syllable span, echoing previous reports that some children with ASD may exhibit subtle phonological memory weaknesses despite otherwise typical language development (Bishop et al., 1996; Jokel et al., 2021). Future longitudinal research is needed to determine whether these phonological memory vulnerabilities in ASD-LN reflect transient developmental delays or precursors of later language challenges.
The Association Between Phonological Memory and Morphosyntax
Our third hypothesis predicted a positive association between phonological memory and morphosyntactic abilities, particularly in the DLD and ASD-LI groups. This prediction was confirmed: Significant associations were observed for both pseudoword and syllable span with morphosyntactic performance, but only in DLD and ASD-LI. This finding supports models that emphasize the phonological loop as a crucial resource for grammatical learning (Baddeley, 2003; Delage & Frauenfelder, 2020; Durrleman & Delage, 2016; Tager-Flusberg, 2015). Regression analyses further showed that phonological memory accounted for variance in morphosyntactic performance beyond general language abilities, underscoring its importance as an independent predictor of morphosyntactic skills.
While our findings are consistent with prior research documenting morphosyntactic and phonological memory deficits in children with DLD and ASD-LI, the present study offers several novel contributions. First, by examining Hebrew, a Semitic language characterized by a uniquely rich system of inflectional and derivational morphology, our results extend existing evidence beyond Indo-European languages. This cross-linguistic perspective strengthens the view that morphosyntactic and phonological memory deficits represent robust cross-linguistic clinical markers rather than language-specific vulnerabilities. Second, our direct comparison of ASD subgroups revealed that children with ASD-LI performed similarly to children with DLD, whereas children with ASD-LN performed comparably to TD peers with only subtle weaknesses in syllable span. These findings refine our understanding of the heterogeneity in ASD and support theoretical distinctions between ASD with language impairment versus ASD without language impairment. Third, our regression analysis demonstrated that phonological memory explained an additional 11% of the variance in morphosyntactic performance beyond nonverbal intelligence and general language ability, underscoring the independent contribution of phonological processing to morphosyntactic development. Taken together, these findings provide important empirical support for both comorbidity models (ASD-LI as a co-occurrence of ASD and DLD-like language difficulties) and multidimensional models (language abilities distributed along continua across diagnostic groups), thereby contributing new evidence to ongoing theoretical debates (Ogundele & Ayyash, 2024; Ramírez-Santana et al., 2019; Willcutt, 2019).
Limitations
This study presents several limitations that warrant consideration. Firstly, the cross-sectional design limits our ability to establish causal relationships between phonological memory and morphosyntactic development. A longitudinal study would track these abilities over time to determine the direction of influence. In other words, although our results revealed significant associations between phonological memory and morphosyntactic performance, these findings cannot be interpreted as evidence of causality. Secondly, the reliance on standardized assessments may not fully capture the nuances of individual language profiles. Further research should incorporate measures of executive functions, such as cognitive flexibility, to account for their potential contribution to morphosyntactic abilities. Additionally, although the current findings indicate that children with ASD-LN had higher scores on the morphosyntactic abilities measure (KHLA) compared to children with DLD, this difference did not reach statistical significance. It is possible that larger sample sizes are needed to detect a significant difference.
Clinical Implications
This study reveals significant clinical implications for the assessment of children exhibiting ASD-LI and DLD as well as for efficacious interventions for these children. The overlapping cognitive profile, characterized by challenges in both morphosyntax and phonological memory, requires interventions addressing both areas. The strong correlations between these skills in preschoolers, coupled with the rapid development of language during these early years, emphasize the critical importance of early identification and intervention in both morphosyntax and phonological memory for optimal language outcomes (e.g., Roberts & Kaiser, 2015).
Footnotes
Author Contributions
The first author was responsible for data collection and authored the initial draft. The second author conceived the original idea and supervised the project. She also played a key role in analyzing the results and writing the manuscript.
Funding
The authors received no financial support for the research, authorship, and/or publication of this article.
Declaration of Conflicting Interests
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Data Availability
Research data supporting this publication are available upon request from the first and second author.
