be known as 意为“作为……而著名”，其后的名词表示一个人的身份、职业等。如：

　　Liu Huan is known as a singer.刘欢作为一个歌手而出名。

　　We’re sure you’ll be well-known as an artist.我们相信你会成为一位著名的画家。

　　be known for 意为“因……而著名”，其后所接内容表示某人或物的特点、特长等。如：

　　Guilin is known for her beautiful mountains and rivers.桂林因其美丽的山水而闻名。

　　Mr Geldof is well-known for organizing two big pop concerts on the same day.

　　盖尔多夫先生因在同一天组织两场大型的流行音乐会而出名。

　　be known to “为……所了解/知道”，其后接表示人的词语。“(人们都)知道”，其后接动词原形。如：

　　He is known to all in our village.村子里的人都了解他。

　　He was known to have invented many things.=It was known that he had invented many things.

　　人们都知道他已经发明了很多东西。

　　be known in 意为“在某地很著名”。如：

　　He is well-known in the town where he was born. 他在自己出生的那个镇子上很出名。