if引導(dǎo)的虛擬條件句【教學(xué)類別】

與現(xiàn)在事實(shí)相反：與現(xiàn)在事實(shí)相反：if條件句用一般過去時(shí)（動(dòng)詞be用were），主句用would(should/could/might)+動(dòng)詞原形、帶、帶if if的虛擬條件句的虛擬條件句與將來事實(shí)相反與將來事實(shí)相反(推測(cè)將來推測(cè)將來)：if 條件句中用過去時(shí)，或should/were to+動(dòng)詞原形，主句用would(should/could/might)+動(dòng)詞原形。與過去事實(shí)相反：與過去事實(shí)相反：if 條件句中用過去完成時(shí)，主句用would（should/could/might）+have+過去分詞。條件從句條件從句結(jié)果主句結(jié)果主句與現(xiàn)在事實(shí)相反與現(xiàn)在事實(shí)相反If +主語主語+過去式過去式 主語主語+would/should/could/might do 與將來事實(shí)相反與將來事實(shí)相反If+主語主語+過去式過去式主語主語+would/should/could/might dowere to do/should/could do)與過去事實(shí)相反與過去事實(shí)相反If+主語主語+had+過去分詞過去分詞主語主語+would/should/could/might have doneIf引導(dǎo)虛擬條件句中的謂語動(dòng)詞變化 He must have had an accident,or he then_.Awould have been here Bshould be here Chad to be here Dwould be there答案為A。or 在這里隱含了與過去事實(shí)相反的虛擬語氣，表示if he had not had an accident,所以其后的主句用would have done 而不用其它的。