2011年职称英语重点语法精讲(12)

来源:微学网发布时间:2011-05-10

  二、不定式

  1、动词不定式形式:(to)+do具有名词、形容词、副词的特征;否定式:not+(to) do

  2、不定式的句法功能:

  (1)作主语:

  To finish the work in ten minutes is very hard.

  To lose your heart means failure.

  动词不定式短语作主语时,常用it作形式主语,真正的主语不定式置于句后,例如上面两句可用如下形式:

  It is very hard to finish the work in ten minutes.

  It means failure to lose your heart.

  常用句式有:

  1、It+be+名词+to do.

  2、It takes sb.+some time+to do.

  3、It+be+形容词+of sb +to do.

  4、It+be+形容词+for sb.+to do.

  常用careless,,clever,good,foolish,honest,kind,lazy,nice,right,silly,stupid,wise,等表示赞扬或批评的形容词,不定式前的sb.可作其逻辑主语.