英语问题,N多久了,我总是搞不懂

be known as: 以...著称，后接名词。例句：John is known as a reliable man.

be known for: 因...而闻名(可是褒意、贬意或中性的)，后后接名词或名词性词组。例句：John is know for his reliability.

be famous for: 以...著名(比known要更出名而且多是褒意或中性的的)，后后接名词或名词性词组。例句：Sichuan is famous for its excellent cuisine.

be known to: 因(某种行为)而被人所知，后接动词。例句：John went to the restaurant where his friend Tom is known to visit.

be known as 后面跟名词，一般是一个职业 he is known as a doctor
他作为一个医生，很出名
be known for sth= be famous for sth因……而著名
be famous for 跟上面一样
be known to sb 为谁所知
he is known to us 为我们共知的

be known as AS后跟一样东西，比如画家，第一大城市，作为这样而被知，具体的事物
be known for 因什么而闻名，可是是具体事物，也可以是一件抽象的事，比如一场战争什么的
be famous for 因一个景象或是类似的显著的特征而出名
be known to 被谁所知，强调对象，比如我们，比如北京人……

be known as 因为某事而为人所知
be known for 因为某事而为人所知
be famous for 因为某事而有名
be known to 在某个方面有名

be known as 作为什么而被人知
be known for 因为什么而被人知
be famous for 因什么为出名
be known to对什么