動(dòng)詞不定式進(jìn)行式表示動(dòng)作正在進(jìn)行，與謂語(yǔ)動(dòng)詞表示的動(dòng)作同時(shí)發(fā)生。如：
He see ms to be recovering.他看來(lái)在康復(fù)。
When he came in，I happened to be lying on the bed，reading. 他進(jìn)來(lái)的時(shí)候，我碰巧正躺在床上看書(shū)。
[英語(yǔ)語(yǔ)法手冊(cè)]非限定動(dòng)詞 E
動(dòng)詞不定式的被動(dòng)語(yǔ)態(tài)
動(dòng)詞不定式有兩種被動(dòng)語(yǔ)態(tài)形式：
一般式to be written
完成式to have been written
例：
The next thing to be done is to carry away the earth.下-步要做的事是把土運(yùn)走。
No harm seems to have been done.似乎并沒(méi)有造成損害。
分裂不定式
有時(shí)在不定式符號(hào)"to"和動(dòng)詞原形之間插入一個(gè)副詞，這種現(xiàn)象叫做分裂不定式(split infinitive)。插入動(dòng)詞不定式的副詞，習(xí)慣上往往與不定式動(dòng)詞連在一起。如：
He likes to half close his eyes.他喜歡半閉著眼睛。
Our object is to further cement friendly relations between the two countries.我們的目的是進(jìn)一步加強(qiáng)兩國(guó)之間的友好關(guān)系。
At first he wasn't interested in bookkeeping，but later he began to actually like it.起初他對(duì)會(huì)計(jì)工作沒(méi)有興趣，但到后來(lái)倒喜歡起它來(lái)了