it做形式主语19个句型.doc

It作形式主语常见句型 1.It is/was + 被强调部分 + that/who ... 该句型是强调句型。被强调部分可以是主语，宾语，表语或状语。强调的主语如果是人，that 可以由 who 换用。如果把这种句型结构划掉后，应该是一个完整无缺的句子。这也是判断强调句型与其它从句的方法。 2. It is not until + 被强调部分 + that ... 该句型也是强调句型。主要用于强凋时间状语，译成汉语 “直到……才……”，可以说是 not ... until ... 的强调形式。 It was not until she took off her dark glasses that I realized she was a famous film star.= Not until she took off her dark glasses did I realize she was a famous film star.= I didnt realize she was a famous film star until she took off her dark glasses. 3. It is clear /obvious/true/possible/certain… that … 该句型中it 是形式主语，真正的主语是 that 引导的主语从句，常译为 “ 清楚（显然，真的，肯定……）”是主语从句最常见的一种结构。 It is very clear that hes round and tall like a tree. 　　= That hes round and tall like a tree is very clear. 4. It is important /necessary/ right/strange/natural... that ...+(should) do 该句型和上一个同属一个句型。由于主句中的形容词不同，that 后的从句中要用虚拟语气（should + 动词原形），should 可以省去。 5. It is said (reported, learned…) that … 该句型中的it 仍是形式主语，真正主语是 that 引导的主语从句。该结构常译为“ 据说（据报道，据悉……）”。 6. It is suggested ( ordered, required ... ) that ... +(should) do 该句型和上一个同属一个句型。主句中的过去分词是表示请求，建议，命令等词时，that 后的从句要用虚拟语气（should + 动词原形），should 可以省。常译为“ 据建议；有命令……）”。 7. It is a pity ( a shame ... ) that ... 该句型中，that 后的从句一般用虚拟语气（should + 动词原形），should 可省去．表示出乎意料，常译为“竟然”。没有这种意义时，则不用虚拟语气。 It is a pity that such a thing ( should ) happen in your class. 这种事竟然发生在你们班上，真是遗憾！ 　 It is a pity that he is ill. 他生病了，真遗憾！ 8. It is time ( about time , high time ) that ... 该句型中that 后的从句应该用虚拟语气，值得注意的是① 常用过去时态表示虚拟．② 有时也用should + 动词原形，should 不能省。常译为“是（正是）……的时侯……”。 9. It is the first ( second … ) time that … 该句型要和上一个句型区别开来。该句型中的 that 从句不用虚拟语气，而用完成时态。至于用什么完成时态，由主句的谓语动词的时态决定。如果是一般现在时，后面从句用现在完成时态；如果是一般过去时，后面从句则用过去完成时态。该结构中 that 可以省去；it 有时用 this 替换，常译为“是第一（二）……次……”。 It is the first time I have been here. = This is the first time I have been here. 10. It is … since ... 该句型主要用作处理瞬间动词的完成时，又要和表示一段时间的时间状语连用的问题。主句中是时间作表语，其时态是现在时或完成时，since 引导的从句通常是一般过去时态，而且是瞬间动词。如果主句是一般过去时，从句则用过去完成时。 11. It i