賓語(yǔ)從句（一）
賓語(yǔ)從句在復(fù)合句中作主句的賓語(yǔ).賓語(yǔ)從句常由that引導(dǎo),在口語(yǔ)中常省略.
當(dāng)主句中謂語(yǔ)動(dòng)詞是現(xiàn)在或?qū)?lái)時(shí)態(tài)時(shí),從句中謂語(yǔ)動(dòng)詞不受主句中謂語(yǔ)動(dòng)詞時(shí)態(tài)的影響,按需要可以使用任何時(shí)態(tài).
如：She says (that) she works from Monday to Friday.
她說(shuō)她從周一至周五上班.（從句是一般現(xiàn)在時(shí)）
She says (that) she will leave a message on his desk.
她說(shuō)她要在他桌子上留個(gè)便條.（從句是一般將來(lái)時(shí)）
She says (that) she has never been to Mount Emei.
她說(shuō)她從來(lái)沒(méi)有去過(guò)峨眉山.（從句是現(xiàn)在完成時(shí)）
當(dāng)主句謂語(yǔ)是過(guò)去時(shí)態(tài),從句中的時(shí)態(tài)一般用表示過(guò)去的某種時(shí)態(tài).
如：He said there were no classes yesterday afternoon.
他說(shuō)昨天下午沒(méi)有課.（從句是一般過(guò)去時(shí)）
He said (that) he was going to take care of the baby.
他說(shuō)他會(huì)去照看這個(gè)嬰兒.（從句是過(guò)去將來(lái)時(shí)）
He said (that) they were having a meeting at that time.
他說(shuō)他們那時(shí)正在開(kāi)會(huì).（從句是過(guò)去進(jìn)行時(shí)）
*當(dāng)主句謂語(yǔ)是過(guò)去時(shí)態(tài),而賓語(yǔ)從句敘述某一客觀真理（事實(shí)）時(shí),賓語(yǔ)從句的時(shí)態(tài)則用一般現(xiàn)在時(shí).
如：The teacher told us(that) nothing is difficult if you put your heart into it.
老師告訴我們世上無(wú)難事只怕有心人.
She said (that) her father is twenty-eight years older than her.她說(shuō)她父親比她大二十八歲.
He said that light travels much faster than sound.
他說(shuō)光傳播比聲音傳播快得多.
賓語(yǔ)從句（二）
由連接代詞或連接副詞引導(dǎo)的賓語(yǔ)從句.
引出名詞性從句的連詞whether和if,在引出賓語(yǔ)從句時(shí),用法和意義相同.但是只能引出賓語(yǔ)從句和不在句首的主語(yǔ)從句,而whether除了引出賓語(yǔ)從句外,還可引出主語(yǔ)從句、表語(yǔ)從句和同位語(yǔ)從句.
例如：
We don't know whether (if) it is right.
我們不知道它是否正確.
The question is whether she should do that.
問(wèn)題在于她是否應(yīng)該做那件事.
Whether it is true remains a question.
是真是假還是個(gè)問(wèn)題.
試比較：
當(dāng)if從句處在主句之后作“是否”講時(shí),引出的是賓語(yǔ)從句.
例如：
I don't know if it is true.
我不知道這事是否真實(shí).
當(dāng)if從句在主句之前作“如果”講,則引出狀語(yǔ)從句.
例如：
I shall go there if I have time.
如果我有時(shí)間,我將到那兒去.