In a lexeme based syntactic theory (e. g., valency theory) fusion of constructions and heads (e. g., verbs) is licensed by the head of the construction. In construction grammar fusion is regarded as a process from the perspective of the construction. An important argument for this view is the existence of constructions that are not licensed by the lexical entry of the verb. Types of constructions motivating this approach are constructions with free datives in German and resultative constructions (constructions with directives or predicatives). The occurrence of this kind of constructions demands an expansion and a revision of current assumptions in valency theory and lexeme based theories in general. (1) It is necessary to add processes of coercion by means of pragmatic implicatures. (2) These coercions take place on the basis of existing constructional patterns built with verbs already fitting these constructions. (3) The non-licensed free datives, directives, and object predicatives are arguments. As arguments they are not captured by the valency criteria of complements versus adjuncts (arguments versus modifiers). The widespread postulate of invariance has to be abandoned in favour of a dynamic kind of prototypicality.