Dutch children temporarily use a possessor se construction with proper/kinship names and pronouns, like dit is Laura-se/opa-se/hem-se jas (‘this is Laura’s/grandpa’s/his coat’). The se possessive is not available in standard Dutch, although examples of it are found on the internet. The se possessive is fully productive with all nouns in Afrikaans. In standard Dutch prenominal possessive constructions show a wide range of variations and restrictions. Dutch children avoid the complexity of the system, but what makes the children apply the se possessive in the first place? I will show that it is due to three properties specific to Dutch. Nevertheless, the se possessive does not persist in standard Dutch as it did in Afrikaans. The Dutch Achilles’ heel might be the early use of weak possessive pronouns.