Previous studies indicate that the completion of a sentence is conditional in terms of tense and lexical collocation and expression. This paper, by turning ill formed sentences into well formed ones, attempts to show that the existence of a syntactic entity in Chinese is dependent on the information structure of the sentence, in other words, the specified information structure is an important element for the existence of an syntactic entity in Chinese. It also shows that there are potential connections between simple sentences and the clauses of the composite sentence and the different types of potential connection make different conditions for the existence of a sentence.