也就是說(shuō)，只要把握好"時(shí)間狀語(yǔ)"和"語(yǔ)態(tài)(先行詞與動(dòng)詞的關(guān)系)"，非謂語(yǔ)動(dòng)詞做定語(yǔ)的考試選項(xiàng)比較容易，出題幾率也比較低。
有人可能會(huì)問(wèn)：
I have a letter to write 和I have a letter to be written兩個(gè)句子中的黑體部分都是做"letter"的定語(yǔ)，為什么一個(gè)用主動(dòng)，另一個(gè)用被動(dòng)語(yǔ)態(tài)。一般來(lái)說(shuō)，當(dāng)動(dòng)詞(write)的行為者就是句子的主語(yǔ)(I)時(shí)，用主動(dòng)語(yǔ)態(tài)。因此，這兩個(gè)句子的內(nèi)涵是有些區(qū)別的。但由于考試形式的局限性，一般不會(huì)考這種區(qū)別的。
4.狀語(yǔ)
非謂語(yǔ)動(dòng)詞做狀語(yǔ)是這一講的重點(diǎn)，也是考醫(yī).學(xué).全.在.線zxtf.net.cn試的重點(diǎn)。大家還記得"句子的連接"一講中說(shuō)過(guò)的"逗號(hào)不能連接兩個(gè)句子"這句話和所舉的例子嗎?
錯(cuò)：He is ill, he cannot come to the party this evening.(逗號(hào)不能連接兩個(gè)句子)
對(duì)：Because he is ill, he cannot come to the party this evening.(使用連接詞)
對(duì)：Being ill, he cannot come to the party this evening.(使用非謂語(yǔ)動(dòng)詞形式)
如果：His child is ill, he cannot come to the party this evening. 該怎么改呢?
道理是一樣的：
His child being ill, he cannot come to the party this evening.
也就是說(shuō)，非謂語(yǔ)動(dòng)詞也要有"行為的主體"，稱為"主格";如果"非謂語(yǔ)動(dòng)詞的行為的主體"與句子的主語(yǔ)不一致，要保留其行為主體(如上句中的"his child")，這種結(jié)構(gòu)稱為"(分詞)獨(dú)立主格結(jié)構(gòu)".
下面每個(gè)例子說(shuō)明一條規(guī)則，注意理解和記憶(重點(diǎn)不要去區(qū)分作什么狀語(yǔ)，也不要刻意去翻譯句子的意思，重點(diǎn)注意形式的轉(zhuǎn)換和規(guī)律)：
1) When she heard the noise, she went out to see what was happening.
Hearing the noise, she went out to see what was happening.
規(guī)則：當(dāng)句子的主語(yǔ)(she)與 (非謂語(yǔ))動(dòng)詞構(gòu)成主動(dòng)語(yǔ)態(tài)時(shí)，只要將實(shí)義動(dòng)詞(heard)恢復(fù)原形 (hear)，后面加ing即可
2) When (或 If) the substance is heated to over 200℃, it will give off a poisonous gas.
Heated to 200 over 200℃, it (= the substance) will give off a poisonous gas.
規(guī)則：當(dāng)句子的主語(yǔ)(it = the substance)與 (非謂語(yǔ)) 動(dòng)詞構(gòu)成被動(dòng)語(yǔ)態(tài)時(shí)，去掉be動(dòng)詞，只保留動(dòng)詞的-ed形式(heated)即可
3) As he did not want to hurt her feelings, he did not tell the truth at the moment.
Not wanting to hurt her feelings, he did not tell the truth at the moment
規(guī)則：非謂語(yǔ)動(dòng)詞的否定式是在非謂語(yǔ)動(dòng)詞前面(不是后面)加not構(gòu)成;其他變化按照例1)或例2)規(guī)定
4) As she has lived in China for over 20 years, she can speak Chinese fluently.
Having lived in China for over 20 years, she can speak Chinese fluently.
As they had not finished the lesso醫(yī)學(xué)全在.線zxtf.net.cnns, the students had to give up going to see the play.
Not having finished the lessons, the students had to give up going to see the play.
規(guī)則：當(dāng)句子中出現(xiàn)1)"for + 時(shí)間"狀語(yǔ)，或2)當(dāng)一個(gè)行為必須在另一個(gè)行為結(jié)束后才能開(kāi)始的情況下，應(yīng)該用"完成式"，否定詞 "not" 要放在"having"的前面，即"Not having…"
提示：當(dāng)你在考試時(shí)分不清是否要用"完成式"時(shí)，應(yīng)傾向于選擇有"完成式"的選項(xiàng)。
5) If weather permits, we'll go out for a picnic tomorrow.
Weather permitting, we'll go out for a picnic tomorrow.
When all necessary data had been collected, they began the experiment.
All necessary data having been collected, they began the experiment.
(注：這個(gè)句子也可以寫成：All necessary data collected, they began the experiment.考試時(shí)按例4)提示選題)
規(guī)則：當(dāng)句子的主語(yǔ)與非謂語(yǔ)動(dòng)詞的主格不一致時(shí)，應(yīng)使用"獨(dú)立主格形式"，其他變化按上述各項(xiàng)規(guī)定處理
需要說(shuō)明的是：
1. 所謂"前置"和"后置"是相對(duì)的，這里這樣區(qū)分一是為了便于理解，二是根據(jù)職稱考試中出題的習(xí)慣，便于判題;
2. 關(guān)于功能，這里只是講了考試中較多出現(xiàn)的形式和結(jié)構(gòu)，對(duì)于諸如如何區(qū)分"目的"和"結(jié)果"等內(nèi)容，因與解題關(guān)系不大，這里就不作具體說(shuō)明了。
下面把非謂語(yǔ)動(dòng)詞中其他幾個(gè)重要問(wèn)題用實(shí)例說(shuō)明一下：
關(guān)于"不定式"作后置狀語(yǔ)的舉例(注意黑體字部分的表達(dá)形式)：
1) She was so angry as to be unable to speak. (她氣得連話都說(shuō)不出來(lái)了。)
2) I don't know her well enough to ask her for help.(我與她不太熟悉，不便請(qǐng)她幫忙。)
3) She was too angry to say anything.(她氣得什么都說(shuō)不出來(lái)了。)
4) I'm only too glad to help you.
注意與例3)的區(qū)別：only too與happy, pleased, glad 等詞使用時(shí)，表示"非常"：我非常愿意幫助你(能幫助你真是太高興了)。
