for sb to do sth用作主語(yǔ)

for sb to do sth在句子中可有作主語(yǔ)。如：

For you to ask Joe would be a big mistake. 你要是去問(wèn)喬，那將是一大錯(cuò)誤。

For Ann to go to France would make me very happy. 安要是到法國(guó)去將使我感到很高興。

注：這類結(jié)構(gòu)通常會(huì)借助形式主語(yǔ)來(lái)表達(dá)，即在句首使用形式主語(yǔ)，而將真正用作主語(yǔ)的“for+賓語(yǔ)+不定式”結(jié)構(gòu)移至句末。如：

It’s too expensive for me to buy. 太貴了，我買不起。

It’s impossible for me to leave my family. 我是不可能離開(kāi)家的。

It’s impossible for the job to be finished in time. 這項(xiàng)任務(wù)要按時(shí)完成是不可能的。

It’s an honour for me to be asked to speak here. 我很榮幸被邀在這里講話。

It’s a new experience for her to be travelling by plane. 坐飛機(jī)對(duì)她是—次新經(jīng)歷。

It’ll take time for her to recover from the illness. 她的病要很長(zhǎng)時(shí)間才能痊愈。

It took twenty minutes for the smoke to clear. 過(guò)了20分鐘煙才散完。