The forms die, dat are used as relative pronouns as well as as demonstrative pronouns. In phrases with prepositions KV prefers welk(e) in relative pronoun (van de welke, buijten 't welk). (De/het) welk(e) is also frequently used as pronoun in subject case. Attributive use of welk is scarce: 080 "Welk denkbeeld met eerste zo vereenigd is, dat het zonder dezelve niet bestaan nogh begreepen kan worden" and welk(e) is almost always preceded by an article (de/ het welk(e)). Welkers is the usual genitive form; welks only occurs once, with a feminine referent. Besides as demonstrative pronoun and conjunction, dat is also used as relative pronoun: 049 "dat deel dat gij met U verstand van haar afsnijd."

Demonstrative pronouns with daar (daar, daaraf, daarbij, daardoor, daarin, daarmede, daarna, daarom, daarop, daartoe, welk, daaruit, daarvan) more often have relative and conjunctive value and sometimes are used instead of forms with waar-.