二、不定式

　　1、動(dòng)詞不定式形式:(to)+do具有名詞、形容詞、副詞的特征;否定式:not+(to) do

　　2、不定式的句法功能:

　　(1)作主語:

　　To finish the work in ten minutes is very hard.

　　To lose your heart means failure.

　　動(dòng)詞不定式短語作主語時(shí),常用it作形式主語,真正的主語不定式置于句后,例如上面兩句可用如下形式:

　　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+名詞+to do.

　　2、It takes sb.+some time+to do.

　　3、It+be+形容詞+of sb +to do.

　　4、It+be+形容詞+for sb.+to do.

　　常用careless,,clever,good,foolish,honest,kind,lazy,nice,right,silly,stupid,wise,等表示贊揚(yáng)或批評(píng)的形容詞,不定式前的sb.可作其邏輯主語.