plat 用 de 还是 het？

Kan jij plat praten?

Can you speak the dialect?

2015, Frans Kellendonk. Verzamelt werk. 2nd ed. (as e-book; original 1st ed. printed 2015), Querido, 2015 (→ISBN; preview at Google Books)

The language is a Bordewijkian artificial language, the figures are not recognisable people, the dialect that they speak is a synthetic dialect. [Note: Bordewijk is a Netherlandic surename.]