The first printed grammar of Dutch, which appeared in 1584, was created by members of the Amsterdam chamber of rhetoric De Eglantier. They presented their text as breaking with traditional ways of dealing with Dutch in the chambers by treating the vernacular as an object of study, by proposing rules, and by rejecting words borrowed from other languages. By studying three cases of rhetoricians active before De Eglantier's grammar was printed this essay shows that the Amsterdam chamber, in fact, took part in an already established tradition of studying the vernacular. These three rhetoricians, Eduard de Dene, Matthijs de Castelein, and Jan van Mussem, were interested in the rules, form, and structure of Dutch, and in how it differed from other languages. All three of them accepted, to a certain extent, loanwords, but they also emphasised the importance of using them carefully and critically. De Eglantier could delve into this pre‐existing learned stance on language. De Dene's case shows, moreover, that language study was not just a theoretical enterprise. Through his poetry, he experimented with neologisms and with the ability of Dutch to incorporate elements taken from other languages, thus exploring the frontiers of his mother tongue.