初三上册英语知识点归纳 to+动词原形 (1)作主语 动词不定式作主语时,(句子)的谓语动词常用单数,其位置有如下两种: (1)把不定式置于句首
如:To get there by bike will take us half an hour
(2)用 it 作形式主语,把真正的主语不定式置于句后,常用于如下句式中
如: It+be+名词+to do Its our duty to take good care of the old
It takes sb+some time+to do How long did it take you to finish the work
It+be+形容词+for sb+to do It is difficult for us to finish writing the composition in a quarter of an hour
It+be+形容词+of sb+to do It is stupid of you to write down everything (that) the teacher says
It seems(appears)+形容词+to do It seemed impossible to save money
在 句 型 中 , 常 用 表 达 客 观 状 况 的 形 容 词 , 如 :difficult,easy,hard,important,impossible,necessary 等; 在句型中,常用careless,clever,good,foolish,honest,kind,lazy,nice,right,silly,stupid,wise 等 表达赞扬或批判的词
在不定式前的 sb,可看作其规律主语
这一句式有时相称于 Sb is+形容词 +to do 句式 ,如: It