This study explored the acquisition of Spanish nominal morphology in 116 children aged 4;0 to 6;11, grouped according to language ability (developmental language disorder [DLD] and typical development [TD]) and bilingualism (Spanish-English bilingual and Spanish monolingual). Monolinguals produced more target-like articles and direct object clitics than bilinguals, as did children with TD compared to peers with DLD. Bilinguals with TD produced more target-like morphology than monolinguals with DLD, particularly clitics. Children with DLD were more likely to omit clitics than peers with TD, but this contrast did not extend to bilinguals compared to monolinguals. Children produced singular default articles in plural contexts. Overall, our results suggest that clitics function better than articles for identifying DLD in bilinguals on quantitative and qualitative grounds. This study explored the acquisition of Spanish nominal morphology in 116 children aged 4;0 to 6;11, grouped according to language ability (developmental language disorder [DLD] and typical development [TD]) and bilingualism (Spanish–English bilingual and Spanish monolingual). Monolinguals produced more target-like articles This area of grammar is also a bottleneck for children with developmental language disorder (DLD), both bilingual and monolingual (Bishop, 2017 ), and the morphosyntactic patterns of children with DLD often resemble those of bilinguals. The similarities in language production between Spanish heritage speakers (HSs) with typical development (TD) and Spanish-speaking children with DLD lead to frequent overdiagnosis of DLD in bilinguals, at rates of up to 40% (Bonuck et al., 2022 ). Overdiagnosis can divert important but limited clinical resources away from children in true need of intervention. The study Because there is not yet a study that distinguishes between bilinguals and monolinguals with DLD and TD at the group level that also considers the nature of differences between these groups’ non-target production patterns statistically, three research questions were proposed: Are there quantitative differences between bilingual and monolingual children with and without DLD in their production rates of Spanish articles and direct object clitics? We anticipated that monolinguals would produce more target-like articles than bilinguals of the same language ability (i.e. Secondly, we believed that including these items, which showed unexpectedly low target-like production rates, could produce misleading results comparing children with DLD and TD on the one hand and bilinguals and monolinguals on the other. 4.3. Procedure Data collection took place between 2014 and 2017, with approval from the Institutional Review Boards of Hospital General Dr. Manuel Gea González (Mexico City), the State University of New York Fredonia, and the University of Houston. Following parental consent and child assent, children completed between two and three 50-minute sessions in their school or at a location designated by caretakers. Similarly, monolingual children produced more target morphology than bilingual peers with the same language ability across sets (i.e. ML-DLD > BL-DLD and ML-TD > BL-TD). Clitics and the combined model revealed statistically significant differences between BL-TD and ML-DLD groups at the p < .05 level, but this contrast was not evident for articles. As children grew older, they produced more target-like morphology across all sets. 5.2. Differences in substitution and omission rates Descriptive findings. There were two models for articles, one incorporating language ability (TD as reference level) as the predictor and the other with bilingualism (monolinguals as reference level) as the predictor. An additional two models prepared for clitics followed the same structure. The results of each model are shown in Appendix 2 . As with the group-level models, we converted log odds to probabilities of substitutions, reported here as percentages. 6 For articles, there was no statistically significant difference in substitutions between children with DLD and TD ( p = .206); however, the difference between bilinguals and monolinguals ( p = .034) was significant. Rather, they should be considered differences in development when bilingual children have a variety of exposure patterns to Spanish at home, school, and the community in comparison with monolinguals who are only exposed to one language, all the time and in all contexts. Our observations of bilinguals only concern one of the two languages that these children speak and, as such, are only intended to represent part of their linguistic development. Consequently, it is desirable to describe this difference in developmental patterns so that bilingual children are not incorrectly penalized when only comparing them to monolingual benchmarks. The positive correlation between target-like production and age in months in all our statistical modelling demonstrates that bilingual children between ages 4;0 and 6;11 continue to acquire Spanish nominal morphology, albeit at a slower rate, than monolinguals. This is no small feat considering that these children are mastering multiple languages with diverging nominal agreement systems simultaneously. These findings are consistent with existing research on Spanish (e.g. Consequently, it would be inaccurate to claim that bilinguals follow a different developmental path compared to monolinguals, even if they move along this path at a slower rate than peers who are tasked with acquiring only one language. On a clinical level, we argue that clitics are of greater value in identifying DLD in bilingual populations on quantitative and qualitative grounds. Firstly, both TD groups produced significantly more clitics than the groups of children with DLD. Secondly, children with DLD were more likely to omit clitics than TD children, but this same contrast did not extend to the comparison between bilingual and monolingual children.