不定式(to do)   　　动词不定式的构成与特征 　　动词不定式是动词的一种非限定形式，由"to+动词原形”构成，在句中起名词、形容词或副词的作用，同时也保留动词的一些特征，可以带宾语或状语，如下: 　　动词不定式:to do相当于①名词(可作主语)；②形容词(可作定语)；③副词(可作状语)。 　　否定式:not+to do动词不定式的功能:   　　雅思写作中动词不定式常作:主语、宾语、表语、定语、状语和宾语补足语。   　　不定式作主语   　　To do this is to cut the foot to fit the shoe. 　　这样做是削足适履。(雅思写作中用来反驳别人观点的杀手锏!)       To subsidize artists and musicians is a wise measure to preserve the traditional culture. 　　资助艺术家和音乐家是保护传统文化的明智措施。( “to subsidize artists andmusicians”在句子中作主语，同时“to preserve the traditional culture”作前面的名词短语“a wise measure”的定语。主语和定语均用不定式，其一，语气强烈;其二，显得很有文采。记住这个句型，在适当的时候运用“乾坤大挪移法”!)       不定式作主语时，往往由“it”代替它作形式主语，不定式则移至谓语之后。   　　It is no exaggeration to say that friendship is to people what perfume is to flowers. 　　可以毫不夸张地说，友谊对于人正如同芬芳对于花儿。(“it”作形式主语，划线部分为动词不定式短语作真正的主语。)       学生常犯错误如下: 　　That is very difficult to find a satisfactory job without a diploma nowadays.(误)       It is very difficult to find a satisfactory job without a diploma nowadays.(正)       现如今，在没有文凭的情况下，要找到一个满意的工作困难重重。   　　不定式作宾语   　　As for those college students from economically humble background，governmental assistance could help to ease the financial burden of rising education costs. 　　对于贫困*生，*的援助可以缓解上涨的学费压力。   　　I believe it best to leave the matter entirely to children's discretion. 　　我认为把这件事情完全交给孩子自行决定是比较好的做法。(“it”为形式宾语，“best”为宾语补足语，“to leave the matter entirely to children's discretion”是真正的宾语。)不定式作表语。   　　The next step is to ensure that all the children in developing countries canhave free access to compulsory education. 　　下一步要确保发展*家所有的孩子能接受义务教育。   　　The first countermove is to lay down more rigid laws and regulations to deterthe would be criminals. 　　*个对策是制定更多严格的法律法规来阻止潜在的犯罪分子。   　　What we should do is to absorb the essence and discard the dregs. 　　我们要做的是取其精粹，去其糟粕。   　　不定式作定语   　　The government should organise some large-scale campaigns to arousepeople's awareness of environmental protection. 　　*应组织一些大规模的活动来唤醒人们的环保意识。   　　Nowadays, with the wide application of computers, many adults feel thepressing need to acquire commuter literacy. 　　现如今，随着电脑的广泛应用，许多成年人感到学习电脑知识的迫切需要。   　　The Internet is a convenient way to convey information. 　　互联网作为传播信息的方式很方便。   　　不定式作目的状语   　　To associate/mingle with friends, we should be honest and open. 　　为了结交朋友，我们应当诚实并且开朗。   　　Our government should take stronger and harsher measures to combat thelittering behaviour. 　　我们的*应当采取更强有力的措施来防止乱丢垃圾的行为。   　　不定式作宾语补足语   　　The 21st century requires us to be equipped with advanced knowledge. 　　21世纪要求我们用先进的知识武装自己。   　　The fierce social competition makes people work and live under greatpressure. 　　激烈的社会竞争迫使人们生活和工作在巨大的压力之下。(此句型为:“make sb.do sth.”，即省略“to”的动词不定式。)   　　Advanced intelligent machines such as robots enable people to work moreefficiently and comfortably. 　　先进的智能机器如机器人能使人们工作得更加高效和舒适。   　　学生常犯错误如下:   　　He hoped his sister to lend him a hand.(误) 　　He hoped that his sister would lend him a hand.(正) 　　他希望妹妹能帮他。   　　He demanded me to give up the chance.(误) 　　He demanded that I give up the chance.(正) 　　他要我放弃那个机会。   　　I suggested him not to go there alone.(误) 　　I suggested that he not go there alone.(正) 　　我建议他不要单独去那里。   　　注意:有些形容词不能用于“人称代词(it除外)+be+形容词+不定式”结构，雅思写作中常用的这些形容词有:probable, impossible, easy, hard, necessary, convenient等。   　　学生常犯错误如下:   　　He is probable to make mistakes.(误)( probable的主语绝不能是人] 　　He is liable to make mistakes.(正)[ liable的主语可以是人] 　　他易于犯错。   　　I am impossible to finish it today.(误)[impossible的主语绝不能是人]。 　　It is impossible for me to finish it today.(正)[ impossible的主语可以是it]。 　　我今天不可能完成这项工作。