it句型归纳复习1．It is said（reported，learned．．．）that．．．该句型中的it是形式主语，真正的主语是that引导的主语从句该结构常译为“据说（据报道，据悉……）”It is said that he has come to Beijing．据说他已经到北京了2．It is．．．since．．．该句型主要用作处理非延续性动词的完成时，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，而且是非延续性动词如果主句是一般过去时，从句则用过去完成时It is（has been）5 years since his father died．他父亲去世已经5年了3．It happens（seems，looks，appears）that．．．该句型中it是形式主语，that引导的是主语从句，主句中的happen，seem等词是不及物动词It happened that he met his teacher in the street．碰巧他在街上遇见了老师It seems that he will be back in a few days．看来他几天后就会回来了。
4．It takes sb．some time to do sth．该句型中的不定式是真正的主语，it是形式主语，常译为“做……要花费某人……时间”It took thousands of people and many years to build the Great Wall．成千上万的人用了许多年的时间才建起了长城5．It is kind（of sb．）to do sth．该句型中的不定式短语是真正的主语，如果不定式的逻辑主语是由of引出的，句中的形容词必须是能表示逻辑主语特征的形容词常见的有：bad，brave，careless，clever，foolish，good（好心的），honest，horrible，kind，lazy，naughty，nice（有教养的），polite，stupid，wise，wrong等这个句型可以改写为：sb．is kind to do sth．It is kind of you to say so．你这样说真是太好了＝You are kind to say so．）6．It is necessary（for sb．）to do sth．该句型与第5点同属一个句型。
如果不定式的逻辑主语是由for引起的，主句中的形容词通常是表示重要性，紧迫性，频繁程度，难易，安全等情况的形容词常见的形容词有：① important，necessary，natural②easy，safe，common，normal，hard，difficult，dangerous，unusual，rare，impossible，pleasant等在①中的形容词作表语可以用从句改写，如：It is important for her to come to the party．＝It is important that she（should）come to the party．7．It looks（seems）as if．．．该句型中it无意义as if引导一个状语从句常译为，“看起来好像……”如果与事实不相符合，则用虚拟语气It looks as if he is ill．（真的病了）It looks as if he were ill．（没有生病）8．We think it important to learn a foreign language．该句型中的it作形式宾语为了记忆方便我们可称该句型为“6123结构。
6指主句中常用的动词：think，believe，make，find，consider，feel；1指的是形式宾语it；2指的是宾补的两种形式：形容词或名词；3指的是真正宾语的三种形式：不定式短语，V-ing短语或that引导的宾语从句We think it our duty to clean our classroom every day．He felt it important to learn English well．They found it difficult that they would finish their work in two days．。