Language competencies are among the most important prerequisites for individual success in education, later participation in the labour market and life in general. In Germany for example, children with delays in language development have a significantly higher risk of experiencing poorer educational and vocational progress than might be expected given their general cognitive skills. This also applies to children with an immigrant background whose first language is not the language of instruction. These children suffer from severe disadvantages related to the lack of competence in the language of instruction. Consequently, impeded participation in society is expected owing to delays in the cognitive, emotional and social development of the children concerned (see Authoring Group Educational Reporting, 2014, for an overview, 2022 for recent summaries).