It is said that there will be an election this week.
There is said to be an election this week.
这2个句子有什么不同？
这两句意思应该相同，但结构不一模一样。句型结构是如此转换来的：
1. People say thatthere will be an election this week. （复句）
2. It is said that there will be an election this week.（复句）
3. There is said to be an election this week.（单句）
大家常说：He is said to be an agricultural scientist. 据了解他是一位农业科学家。
原来，这个句子是如此转换来的：
A. People say that he is an agricultural scientist.
B. → That he is an agricultural scientist is said.（因主语太长，看上去头重脚轻。大家一般使用形式主语It替代真实主语that从句，见C句。）
C. → It is said that he is an agricultural scientist.
D. → He is said to be an agricultural scientist.
转换的结果是，He作了主语，is said意为“被说”，to be an agricultural scientist成为动词不定式。
据此，从理论上讲，there be 句型假如充当了某个及物动词的宾语从句，那样，这个及物动词，就能用于上述句式的转换。比如：
1. People say that there will be an election this week.
→ It is said that there will be an election this week.
→ There is said to be an election this week.
【注意】不定式本身表示以后，所以will 不再出现，不可以说There will be said to be...。