The relation between numeral acquisition and morphosyntactic cues in kindergartners with and without (suspected) Developmental Language Disorder.

<p><br></p><p dir="ltr">Children benefit from morphosyntactic cues such as grammatical number marking and derivational rules when learning cardinals and ordinals (e.g., Almoammer et al., 2013; Schneider et al., 2020; Meyer, 2019). However, children with Developmental Language Disorder often have difficulties with morphosyntax (Leonard, 2014). We therefore hypothesized that children with DLD cannot use morphosyntactic cues to the same extent in their numerical development. We investigated this by comparing the performance of 27 kindergartners with (suspected) DLD (4;04-6;09) and 42 TD peers (4;03-6;04) on two counting measures (Rote Counting & Next Number (Schneider et al., 2020) and two measures of numerical knowledge (Give Me (Wynn, 1992), and Tell Me (Meyer, 2019)). The study also explored how verbal and non-verbal background measures predicted children’s counting ability and ordinal comprehension. In line with previous research, we found that children with DLD experience difficulties with counting (Cross et al., 2019). In addition, our results revealed substantial delays in ordinal acquisition and qualitative differences between the groups. Unlike TD peers, children with DLD frequently interpreted ordinals as cardinals, and they also failed at different points in the counting routine. We therefore argue that children with DLD benefit less from morphosyntactic rules than TD children when learning numerals. This was further substantiated by the fact that differences between the tasks were mediated by language abilities, and by interaction effects which suggested that morphological knowledge contributes more to counting abilities in TD children than in children with DLD. These findings shed new light on numeracy deficits associated with DLD.</p><p dir="ltr">This collection contains the experiment files and analysis files (data files, R scripts, and html files) that belong to the study titled "When children cannot count on morphosyntax: the relation between numeral acquisition and morphosyntactic cues in kindergartners with and without (suspected) DLD." These data were collected and analyzed as part of the research for a dissertation written Heleen de Vries, under supervision of Judith Rispens, Caitlin Meyer, and Alla Peeters-Podgaevskaja.</p>