(1)与but一样，expect后面除了像其他介词一样可跟名词和代词外，还可跟介词短语、不定式和从句。
They were all rescued except the captain,who stayed behind to safeguard the vessel.(名词).
Everybody is here except him.(代词).
The weather in the area will be fine tomorrow except in the southeast,where we will have some drizzle.(介词短语).
To point out his mistake directly will have no effect except to make him angry.(不定式).
I don’t know much about London except that it is the capital of Britain.(从句).
注意：在do nothing/everything/anything except的句型中，其后的不定式多省略to。
They could do nothing except wait for help to arrive.
I’ll do everything for you except wash your underwear.
(2)except和except for的区别.
except后面的成分和主语或宾语的成分属于同一种类，而except for后面的成分跟主语或宾语的成分不属同类。
The office was empty,except for a desk and a chair.(the office与a desk and a chair不同类).
All the students in the class went to the lecture except Li Hong.(Li Hong也是个student).
(3)but和except的区别
but后面的成分一般不重要，而except则强调它后面所跟的成分，but多放在否定句或否定词nobody,nothing等之后，而except则不一定。
For a while,there wasn’t anything to do for either of us but drink beer.
My papers seem to be everywhere except where they ought to be.