下面罗列的这类现象，来自我日前见到的一篇有趣的论文。
关于这类现象，现在理论语言学界还没达成协议。关于怎么样打造能准确预测这类现象的理论，大伙可以自由地发表设想。
（如此的理论现在并非没有，但它需要对代词和限定词的定义作出很彻底的重组和改革。如此的改变，恐怕在几十年内英语教学界都是无人能同意的）
1)有时候，表达一个具体的时间或地址的名词词组不可以用it代替：
错误：I went swimming in December, and John went swimming in it too.
错误：I ate dinner on the fourth floor, and John ate dinner on it too.
2)然而若是不够具体的时间或地址，就能用it代替：
正确：Everyone who likes a winter month goes swimming in it.
正确：Everyone who likes a particular floor eats dinner on it.
3)具体的时间偶尔又可以用it代替：
正确：I spent June at the pool. It is my favorite month.
正确：I spent June at the the pool, but John spent it in his office.
4)除去时间和地址，还有不少名词词组存在这种不可以用it替代的现象。上世纪末Paul M. Postal曾对这类结构做过总结，并将它们称为Antipronomial Context：
错误：He named his daughter Lucille, but I didnt name mine it.
正确：Everyone who dislikes their name wishes they were never named it.
错误：They painted their porch green, but I refused to paint my porch it.
正确：Everybody who likes some shade of green also paints their porch it.
5)有的结构又会解除这种不可以用it替代的限制：
错误：John ate turkey on Thanksgiving. Jim ate turkey on it too.
正确：Every American who ate tofu on it remembers the Thanksgiving of 1977.
正确：Most Americans celebrate Thanksgiving. Some eat turkey on it.
正确：John avoids his family on Thanksgiving. Everybody else sees their family on it.
1) 有时候，表达一个具体的时间或地址的名词词组不可以用it代替：
错误：I went swimming in December, and John went swimming in it too.
错误：I ate dinner on the fourth floor, and John ate dinner on it too.
【答】有时，语言表达出现错误，并非语法上的错误，而是逻辑上的错误，或者不符合惯使用方法，或者啰嗦累赘，总之，错误在于不符合语言表达的基本规律。上两句被判错误，其实与it 指代的事物“是不是具体”无关。由于第二个并列分句几乎完全重复了第一分句的内容，所以看上去啰嗦、累赘，不符合语言的表达规则。可以改为简练的表达方法，如：and so did John.
表达一个具体的时间或地址的名词词组，果真不可以用it 代替吗？那样，大家把第二分句改一下，用it 是完全可以的：
I went swimming in December, and it was not a very cold month here.
I ate dinner on the fourth floor, and it was crowded with people.
下面的Her birthday 和 His house，都是具体的时间或地址的名词词组，完全可以用it 代替：
Her birthday is coming, and she is now preparing for it.
His house is small and dirty, but he likes it very much.
2) 然而若是不够具体的时间或地址，就能用it代替：
正确：Everyone who likes a winter month goes swimming in it.
正确：Everyone who likes a particular floor eats dinner on it.
【答】时间名词、地址名词，具体和不具体都没关系，都可以用it代替，见1)解答。
3) 具体的时间偶尔又可以用it代替：
正确：I spent June at the pool. It is my favorite month.
正确：I spent June at the the pool, but John spent it in his office.
【答】该问题仍然跟是不是具体时间无关。不是“偶尔”，而是“非常常常”，见1)解答。
其实，前3个问题是一回事，可以概括为一个内容。我觉得，无论时间名词还是地址名词（包含表示其他事物的名词）表达的意思具体与否，当第三提到时，都可以用it 代替。
4) 除去时间和地址，还有不少名词词组存在这种不可以用it替代的现象。上世纪末Paul M. Postal曾对这类结构做过总结，并将它们称为Antipronomial Context：
错误：He named his daughter Lucille, but I didnt name mine it.
正确：Everyone who dislikes their name wishes they were never named it.
错误：They painted their porch green, but I refused to paint my porch it.
正确：Everybody who likes some shade of green also paints their porch it.
【答】复合宾语中的补足语，通常不需要it。这一句They painted their porch green, but I refused to paint my porch it. 中更是这样，it没办法代替形容词green。
5) 有的结构又会解除这种不可以用it替代的限制：
错误：John ate turkey on Thanksgiving. Jim ate turkey on it too.
正确：Every American who ate tofu on it remembers the Thanksgiving of 1977.
正确：Most Americans celebrate Thanksgiving. Some eat turkey on it.
正确：John avoids his family on Thanksgiving. Everybody else sees their family on it.
【答】第一句的错误重复了第一个问题的错误。后面的句子之所以正确，是由于句子的内容没重复。比如：Most Americans celebrate Thanksgiving. Some eat turkey on it. 这句话说了两个内容：大多数美国人庆祝感恩节，在（感恩节）这一天有些人吃火鸡。
【个人看法】从这类问题看出，写这篇论文的作者过分重视了句子的外在形式，而忽视了句子的内容。因此，可能误导我们的看法。
