这个句子包含了什么语法，为什么用considered

Question

there is a new hospital considered to be the biggest one in our city

Answer 1

considered to be the biggest one in our city 是分词短语做定语修饰hospital，不能独立成句。There is a new hospital 是主句，可独立存在。

原句相当于 There is a new hospital which is considered to be……which 引导的定语从句修饰hospital。
原句which is被省略，而hospital是“被认为……”——considered；hospital是物，不会“认为……”——considering。
be considered to be 是一个固定词组，这里be可以省去。

Answer 2

语法是considered to be过去分词作后置定语修饰hospital
用过去分词是体现了一个被动关系 considered to be意思是 被认为是

Answer 3

定语从句，“医院”是“被认为”的！