1 不定式to do, in order to do something （这些不定式的逻辑主语是主句的主语）
In order to attract visitors, historic buildings should be maintained.
错误的原因：历史建筑是没有生命的，不可能有“in order to”
正确的句子：In order to attract visitors, city councils should maintain historic buildings.
2 when, while, before, after 等连词引导的现在分词或者动名词 （这些分词或者动名词的逻辑主语也是主句的主语）
例句：When communicating with others, patience is important.
正确的句子：when communicating with others, one should show patience.
3 by+doing （这些动名词的逻辑主语是主句的主语）
例句：By setting rules, children can reduce behavioural problems.
正确的句子：By setting rules, schools can reduce behavioural problems.
4 Compared with （这些过去分词的逻辑主语是主句的主语）
例句：Compared with Japan, the crime rate in the US was high.
错误的原因：分词compare的主语应该是the US， 而不是the crime rate
正确的句子：Compared with Japan, the US had a higher crime rate.
事实上原句是： when the US is compared with Japan, the US had a high crime rate.
5 enable somebody to do something （这些不定式的逻辑主语是enable后面那个名词）
例句：Education has enabled young people to increase knowledge and reduce poverty.
错误的原因：后面的reduce poverty逻辑主语是young people，而不是education， 而young people不会reduce poverty.
正确的句子：Education has reduced poverty because it enables young people to increase knowledge and find work.
6 make it possible/difficult for somebody to do something （这些不定式的逻辑主语是for后面那个名词）
例句：Modern farming techniques have made it possible for children to deal with hunger.
错误的原因：后面to deal with的逻辑主语不是farming techniques, 而是children, 而children不可能deal with hunger
正确的句子：Modern farming techniques have made it possible for many countries to deal with hunger.
7 分词结构 （很多时候，句子末尾的现在分词的逻辑主语是前面主句的主语）
例句：Many companies have required employees to work overtime, performing all tasks before going home.
正确的句子：Employees are required to work overtime in many companies, performing all tasks before going home.