Through the use of lexical or syntactic means ditransitive constructions which are ambiguous in giving or taking can be clarified as a result of unaccusativization and unergativization respectively. Unaccusativization weakens the agentivity of subject and profiles the predicate to be a result or final state, which, as a result, drives the implicit predicating structure to assume a negative existential structure. Unergativization strengthens the activity displayed by the predicate and motivates the implicit predicating structure to assume positive existential structure. In this way the meaning of ditransitive construction can be proved to be either leftward or rightward transfer, whose reliability can be testified by the use of giving and taking verbs. What is given or taken may be either physical or nonphysical, in this case, bidirectional transfer of benefit and cost can be concluded. Such is the meaning of ditransitive construction.