1）apart from就比较复杂了.apart from = in addition to/besides + except (for)也就是说apart from兼有上述三种用法.
2）except指同类排除,即前后名词属于同一属性.如：All the students went there except Tom.其中students和Tom为同一属性.
3.）except for指整体中的细节修正,即前后名词为整体/局部的关系.如：The house is nice except for the chimney.The article is well written except for some spelling mistakes.其中的the house和the chimney,the article和some spelling mistakes之间就是整体和局部的关系.
4）besides不能加that,是指besides不能加上that引导的宾语从句,但是except可以加上that/when/what引导的从句.原因就在于,能加that引导的宾语从句的介词很少,一般只有except/in.如：The girl is very beautiful except that her hair is a little grey.I walk to school every day except when it rains.I believe you except what you told me just now.
5）in addition to = besides指内部互斥,即前后名词可以合为一个整体.如：The other students also went there besides/in addition to Tom.其中的the other students和Tom可以合为the students,并且“两部分都去了”.