一、except, except for都表示“除......之外（其余）都......"。
except, except for用于将其后事物排除在前述情况之外，不包含在前述情况之内。
I like all fruit except (for) oranges. 除了桔子外其余的水果我都喜欢。（把桔子排除在喜欢的水果之外）
She likes going to most sports events, except(for) cricket matches. 除了板球，绝大多数体育项目她都喜欢。（把板球排除在喜欢的运动之外）
借助词源可以更好的记住except (for)表示“不包括在内“的用法，前缀ex-表示”向外“，而词根-cept-表示拿，except的字面意思为“拿到外面，拿出来”，“拿出来”了当然不包含在（前述情况）内了。
二、位于句首时用Except for不用except。
Except for Louisa, who’s away in Berlin this weekend, we’ll all be at the party.除了这个周末去柏林的Louisa，我们都将参加晚会。
三、跟从句时用Except不用except for。
The brothers are very alike, except (that) Mark is slightly taller than Kevin. 两兄弟很像，就是Mark比Kevin稍高点。
接下来我们看看except (for)与besides的区别：
如果我们把except (for)的意思记为“除......之外（其余）都......"（表不包含在内），那么我们把besides的意思记为”除了......之外还/也（表包含在内）
What other types of music do you like besides classical?除了古典乐，你还喜欢什么类型的音乐？
Besides being heartbroken, she felt foolish. 除了心碎，她还觉得很傻。
扩展资料：
1、在否定句中，besides 也表示“除??之外不再有?? ”，与but, except 同义。如：
No one passed the exam besides [except] Jim. 除吉姆外，没一个人通过考试。
2、关于 but 与 except：
(1)两者都可表示“除??外不再有??”，但含义上略有差别：but侧重指意义的几乎完整性，而 except 则侧重指后面除去的部分。比较：
All are here but one. 除一个人都到了。
All are here except one. 还有一个人没到。
(2) but 一定不能用于句首，except 通常不用于句首：
正：Everyone is tired but (except) me.
正：Everyone but (except) me is tired.
误：But (Except) me, everyone is tired.
3、 关于 except for 与 but for：
except for 主要表示排除，but for 主要表示一种虚拟条件(与虚拟语气连用)。如：
Except for me, everyone passed the exam. 除了我之外，大家都通过了考试。
But for my help, she would not have passed the exam. 若不是我的帮助，她就不会通过考试。
2.except 后一般可跟名词性从句,except此时为连词,except for为介词短语,不接从句.换句话说,即介、连词前只能用except
I like her except when she is crying.
I can't spare any time except on Saturday.
3.在以except连接的句子中,可将except的某些词与其后的词重新组成一个语义完整、逻辑通顺的句子
He desired nothing except to see Chairman Mao.
He desired to see Chairman Mao.
The room was virtually empty except for a bench or two.
The room was a bench or two (不成立).
4.except for含有大体上可以,但有部分不够好,“美中不足”,有令人“惋惜”之意
Achilles was invulnerable except for his heels.阿基里斯除脚踵外,全身刀枪不入.
5.except for之前说明句子的基本情况,而其后部分则引述了相反的原因或细节,“非同类比较”,意为“要不是”,“只是”
The carpet is good except for its price.地毯很好,只是价钱太高.
6.在一些含有except for的句子中,如可以把except for之前的某些词与其后的某些词组成一个独立的句子,则except for与except可以互换使用,但在书面语中常常用except
Everybody had a wonderful time except for John.(except for =except)
重新组合句子为：John had a wonderful time.
7.在all,any,every,no,anything,anybody,anywhere,whole这些表示总体概念的词后面,可用两者：except或except for,其他情况用except for
We are all here except / except for John.
8.句首不能用except,而用except for
Except for John,we've all here.
9.except前后的词(名、代)是平行的,应是同性质的词,否则用except for
The students exercises are good except John's.
Your exercise is good except for a few spelling mistakes.
10.besides与but意义不同,但用在no或not等否定词后面,意思相同
We have no other tools besides / but these.除这些以外,我们没有别的工具.
11.except较but除外的意思更明确,排除性更强,except所述的事物不在总体范围之内
I've written all my letters but one.
We all went except Mary.
12.在否定句中except与besides可互换使用,except for则不能
No one writes to me except / besides you.