The purposes of the paper are; first, to show that verbal nouns in light verb constructions are nominal instead of being nominal plus verbal and, second, to show that the light verb constructions reflect typological variations between English-type isolating languages and Korean/Japanese-type dependent marking languages (Nichols 1986). English-type languages are predicate centered, meaning that predicates select arguments. On the contrary, Korean and Japanese are argument centered. They allow arguments to combine in a cluster and to select their predicate. Then, the special properties of light verb constructions are not from the dual category but from the dual character of verbal nouns they are not only selected by preceding arguments but also select another verbal nouns or a light verb.