短语部分没有独立主语，则短语结构称为非谓语动词。
　　非谓语动词的结构：分词(分词短语)
　　句子的主语决定非谓语动词中的分词是用主动还是被动形式。如果是句子的主语发出动作，则使用现在分词;如果动作不是由句子的主语发出，则使用过去分词。
　　1.No matter how frequently _A_， the works of Beethoven always attract large audiences.
　　A performed B performing C to be performed D being performed
　　perform vt. 表演，演出，演奏;
　　to be performed 将要被演奏; being performed 正在被演奏;
　　一些特殊的动词：
　　第一点：forget 忘记; [反义] remember 记得;
　　这两个词后加动词不定式表示将要进行的行为;这两个词后加动词ing形式表示已经做过的事情。
　　注意：动名词与现在分词形式一样，但含义不同。这两个词后加动词ing形式都是动名词。
　　forget to do sth. 忘记要去做某事; forget doing sth. 忘记做过某事;
　　remember to do sth. 记得要去做某事; remember doing sth. 记得做过某事;
　　2. I remember _B_ to help us if we ever got into trouble.
　　A once offering B him once offering C him to offer D to offer him
　　offer vt. 提出，提供; offer sb. sth. / offer to do sth.
　　him once offering 如果改成 his once offering 也正确。
动名词的复合结构：凡是一个动词的后面可以加动名词，就可以加动名词的复合结构。
　　动作发出者 + 动名词;当动作发出者名字给出时：名词所有格 + 动名词;当动名词的复合结构在文章中出现，且动作发出者在前文中提过时：形容词物主代词(宾格)+ 动名词。
　　形容词物主代词：his， her， my， your， their， our。代词宾格：him， her， me， you， us， them。
　　第二点：want 想要; want to do sth. 想做某事; want doing 客观需要或缺乏。
　　例. Your hair wants _B_. You’d better have it done tomorrow.
　　A cut B cutting C to cut D being cut
1. The children went there to watch the iron tower _D_.
　　A to erect B be erected C erecting D being erected
　　watch 看电视用，看比赛用; see 看电影用;
　　感官动词watch， see， hear; 感官动词 + 名词(代词)+ do
　　be erected 强调的是动作的结果; being erected 强调的是动作的过程。
　　2. The engine _D_ smoke and steam.
　　A gives up B gives in C gives away D gives off
　　give up 放弃; give in 屈服，让步; give off 释放，放出(烟和气体);
　　give away 泄露，走漏风声;婚礼中新郎的父亲把新娘的手交给新郎的过程;赠送礼品。
　　3. The manager promised to keep me _C_ of how our business was going on.
　　A to be informed B on informing C informed D informing
　　keep sb. + 分词; inform v. 通知，告知; inform sb. of sth. 通知某人某件事情
　　keep me informed 使我被告知。
　　4. The goals _B_ he had fought all his life no longer seemed important to him.
　　A after which B for which C with which D at which
　　fight with sb. (注意要看整个句子); fight with + 工具 用该工具来打仗。 fight for 为…而战。
　　I fight with him. 我和他打起来了。 I fight with him against her. 我和他并肩对付她。
5. They _C_ in spite of the extremely difficult conditions.
　　A carried out B carried off C carried on D carried forward
　　in spite of 尽管; carry on 坚持，继续。
　　注意：want doing 中doing表示的是被动含义。
　　例. This room is so dirty that it wants _A_.
　　A cleaning B to clean C being cleaned D cleaned
　　第三点：mean 意味; mean to do sth. 打算做某事，意欲… ;mean doing 意味着，…的意思是…
　　例. There’s a man at the reception desk who seems very angry and I think he means _B_ trouble. [reception desk 接待台]
　　A making B to make C to have made D having made