Here is a question about this article: Like in English, Dutch has generalised the dative over the accusative case for all pronouns, e.g. Du me, je, Eng me, you, vs. Germ mich/mir dich/dir. There is one exception: the standard language prescribes that in the third person plural, hen is to be used for the direct object, and hun for the indirect object. This distinction was artificially introduced in the 17th century by grammarians, and is largely ignored in spoken language and not well understood by Dutch speakers. Consequently, the third person plural forms hun and hen are interchangeable in normal usage, with hun being more common. The shared unstressed form ze is also often used as both direct and indirect objects and is a useful avoidance strategy when people are unsure which form to use.
What is the answer to this question: When did the grammarians first draw the line between third person plural pronouns for Dutch?
17th century