“Wel iet wat verschelende, maar zó niet óf elck verstaat ander zeer wel”

This paper delves into language differentiation in the 16th and 17th-century Low Countries, focusing on how vernacular languages were labeled and framed in grammatical descriptions. We examine both monolingual grammars as well as grammatical descriptions in multilingual textbooks for foreign language learners. By comparing these two corpora, we gain insights into the differences between monolingual and multilingual approaches to language differentiation and uncover language ideologies that shaped the Language-Making process during this early stage of standard languages. An example of language differentiation is the evolving relation between ‘Dutch’ and ‘German’. In the monolingual grammars, Dutch is explicitly positioned along the lines of an ‘ours’ versus a ‘theirs’, but what is considered ‘ours’ differs between the grammars and changes over time. In the multilingual textbooks, the direct juxtaposition between Dutch and German on the title page leads to distinct labels (‘Nederduits’ vs. ‘Hoogduits’) whereas there is no consistent distinction in the body of these textbooks until the late 17th century. Overall, we conclude that a ‘Dutch language’ was certainly being ‘made’ during this period, in name and in reference to other vernacular languages. However, its boundaries were still fuzzy, reflecting the multilingual reality of the early modern Low Countries.