四六級(jí)常考語法點(diǎn)預(yù)覽：

一、虛擬語氣

基本規(guī)則：

條件從句

主句

與現(xiàn)在事實(shí)相反

動(dòng)詞過去式

should/would+動(dòng)詞原形

與過去事實(shí)相反

had+過去分詞

should/ would +have+過去分詞

與將來事實(shí)可能相反

動(dòng)詞過去式/were to/should

should/ would +動(dòng)詞原形

與現(xiàn)在事實(shí)相反：

If I wereyou , I would apply forthe job.

與過去事實(shí)相反：

If I had taken your advice, I wouldn’t have made such mistake.

與將來事實(shí)相反：

If itrained tomorrow, I wouldstay at home.