An acquisitional view on optionality

This paper argues that true optionality does exist. It is even inherently tied up with the procedure of parameter setting in child language [Kampen, J. van, Proceedings of the Workshop on Optionality (1995), OTS, Utrecht University]. The marked value of a parameter is set by adding a grammatical feature to a lexical category. The enriched category requires a mere specific licensing and will in general block its initial less specified default variant. The default variant survives sometimes, leading to optionality. Two clear cases of optionality are presented here. The first case is pied-piping in Polish adult and in Dutch child language, the second case is long reflexives in Dutch. The two cases show how the optionality may be due to an independently existing licensing possibility within the same grammar. The alternative explanation by Kroch [J. Lang. Variat. Change 1.3 (1989) 244], Roeper [Bilingualism: Language and Cognition 2(3) (1999)] and Yang [Oxford University Press (2002)] of two co-existing grammars is rejected by the present proposal.