According to the definition of Kai in Modern Chinese-Sixth Edition (2015:717), there are eleven words with word functions. Because the complement of 開 has almost no verb-derived nouns, no prefix function, but suffix function, and no functions of different grammatical categories, 開 is not regarded as a light verb. It is a real verb, analyzing its syntactic features one by one, and the results are as follows: 1) ergative verb The “開” of ergative sentences has the semantic characteristics of [+cause], [+change of events] when they constitute binary structure sentences, and [+change of events] when they constitute unitary structure sentences, they have the semantic characteristics of [+change of events], [unbounded change of changes]. 2) one argument unaccusative (1) The unaccusative sentence has no specific cause, which can be divided into experiential sentence and existential sentence: at this time, “開” has the semantic characteristics of [- cause], [+change of the event], and the change of the event has no natural termination point, that is, [unbounded change]. However, those who experience sentences are those who do things, while the existential sentence is the place where the experience is. （2) When the term K (liquid boils when heated), only the experiential senten-ce, “CAUSE + 開” has the verb “burn” to replace it. 3) two argument unaccusative (1) When it has the semantics of [+appearing] or [+disappearing], it can form existential sentences. At this time, ‘開’ has the semantics characteristics of [+cause], [change of events], and this change has no natural termination point. (2) The opening of binary unaccusative sentences of [+bounded] has the sem-antic characteristics of [+cause], [change of events], and this change has a natural termination point, that is, [bounded change], which can not constitute an experiential sentence at this time. (3) The “open” of [+conditional unbounded] constitutes a binary structure, which has the semantic characteristics of [+cause]; when the time quantifier is added, it can form a unitary structure, which has the semantic characteristics of [+change unbounded], but this change can only last for the period indicated by the time-quantity complement.