The prototype of the “chufei(除非)” sentence is “chufei(除非) p, cai(才) q, fouze(否則) -q”. “chufei” sentence will divide the sentence into six kinds: A-type: chufei p, fouze q, B-type: chufei p, fouze -q, C-type: chufei p, -q, D-type: chufei p, q, E-type: -q chufei p, F-type: ruguoxiangyao(如果想要) q, chufei p. ‘chufei’ sentence pragmatically divides the relationship between condition p and result q into two categories, the direct condition relationship and the inverse condition relationship. Among them, “p is q” is a conditional relationship, indicating ‘special circumstances’. The focus of the A-type is placed on the condition p of the special case, the D-type is described from the objective angle, the focus is placed on the special case (p is q), and the F-type puts the result q to the front of the sentence, and the focus is on the result q. And “ruguoxiangyao(如果想要)” and “cai(才)” are the focus markers that emphasize the conditional result q. There are three types of inverse conditional relations, namely B-type, C-type, and E-type. ‘fouze (-p), -q’ is an inverse conditional relationship, indicating ‘general circumstances’. Among them, the B-type is a marked sentence of the inverse conditional sentence, and the C-type is an unmarked sentence. The mark ‘fouze’ indicate the inverse condition appeared between The end of the Qing Dynasty and the early Republic of China. Therefore, the C-type was formed first, andthe B-type appeared due to the communication needs. Basically, the focus of the inverse conditional relationship is on the general circumstances. The focus of the B-type is placed on the condition(-p) of the general circumstances, the focus of the C-type is placed on the result(-q) of the general circumstances. and the result(-q) of the general circumstances of the E-type is prepended to the beginning of the sentence, so it emphasizes conclusion -q of the general case more than the C-type.