The present study provides a minimalist account of diverse semantic and syntactic patterns found in three different types of clausal complements selected by factive and non-factive predicates in Korean. It will be shown that Korean challenges the widely-held dichotomous views on factive and non-factive sentential complements, such as the presence vs. absence of presupposition and the presence vs. absence of islandhood. We argue that the semantic and syntactic behavior (factivity and islandhood) of the clausal complement is determined by the interplay between two related factors, the type of the matrix predicate (factive vs. non-factive) and the type of the clausal complement in Korean.