Something that is impossible cannot be done or cannot happen.
It was impossible for anyone to get in because no one knew the password.
任何人都不可能进得去,因为没人知道密码。
He thinks the tax is impossible to administer.
他认为税金没办法管理。
An impossible situation or an impossible position is one that is very difficult to deal with.
I think he was in an impossible position.
我想他当时处于一个极难应付的境地。
If you describe someone as impossible, you are annoyed that their bad behaviour or strong views make them difficult to deal with.
intolerable
The woman is impossible, thought Francesca.
弗朗西丝卡暗自思忖,这个女人真让人受不了。
The impossible is something that is impossible.
They were expected to do the impossible.
他们被要求去做不可能的事。