The paper explores an interesting case where two distinct patterns of excessive predication are apt to be mistaken as a free grammatical alternation without a semantic change. The patterns involve the use of an excessive marker si ‘die’, in predicating an extreme emotion, as in Wo xianmu si ta de haoyun le ‘I am envious of his good luck to death.’ vs. Ta de haoyun xianmu si wo le ‘His good luck made me envious of him to death.’ Different from traditional approaches to the seeming form-meaning mismatch, this paper proposes that the two highly correlated expressions be viewed as two distinct “constructions” defined in the notion of Construction Grammar (Kay & Fillmore 1999, Goldberg 1995, 2006):Excessive Degree Construction (EDC) vs. Excessive Impact Construction (EIC).The two constructions arise from two types of grammatical packaging in response to two different semantic perspectives. The degree-measuring EDC profiles an Experiencer-to-Stimulus relation, conforming to the default pattern of stative predicatio ; the impact-depicting EIC profiles an Affector-to-Affectee relation,projecting a more dynamic, eventive scenario where a victim undergoes an affective impact. Illustrated with live examples from web corpora, the two constructions are further contrasted with a thorough discussion of their grammatical and semantic correlates. The case under study demonstrates how conceptual alternation can result in constructional alternation, whereby the surface word order change manifests a change in semantic relation. The study ultimately probes into the possible range of syntax-semantics interactions realized in Mandarin.