一、besides 意為“除了……,（還,也）”,表示的是追加關(guān)系,整體中包括了“除了”的部分；
Five other representatives arrived late besides me. 除了我還有五位代表來晚了.（晚到的代表中包括“我”）
Besides his wife, his daughter also went to see him. 除他妻子外,他女兒也去看過他.
二、except 意為“除了……,（其余的都）”,表示的是剔除的關(guān)系,整體中不包括“除了”的部分,except 除了后面接名詞、代詞外,還可接介詞短語或從句.
All the other five representatives arrived late except me. 除了我,其他的五位代表都來晚了.（晚到的代表中不包括“我”）
I seldom go by bus except when it is rainy. 除了下雨的時(shí)候,我很少乘公共汽車.
He rarely went anywhere except to his office. 除了去辦公室,他很少去別的地方.
I know nothing about it except what he told me. 除他告訴我的情況外,我對此事一無所知.
My papers seem to be everywhere except where they ought to be. 我的文件似乎完全不在它們應(yīng)該放置的地方.
三、except for 表示的是,在整體上給以定論后,再從局部上加以修正.與except 不同的是：except 所“排除”的部分與前面所述整體詞屬于同類,是部分與整體的關(guān)系；而except for 所“排除”的部分與前面所述的整體詞往往不是同類.如：
Your essay is well written except for one or two minor grammatical mistakes. 你的作文除了一兩處小的語法錯(cuò)誤外,寫得很好.（“作文”與“語法錯(cuò)誤”不是同類事物）
若用于句首,則 except for 與 except 同義(但 except 通常不用于句首,另外but也不能用于句首)：
Except for me, everyone passed the exam. 除了我之外,大家都通過了考試.
四、 but與except的用法基本相同并常互換使用,但but多與no, nothing, not anything, nobody, nowhere, all, anything, who等詞連用,but所引出的事物常是句子的重心,有一定的強(qiáng)調(diào)意味.如：
They are all from the countryside but / except John. 除了約翰外,他們都來自鄉(xiāng)下.
I never saw him reading anything but the newspaper. 除了報(bào)紙,我從沒見他讀過別的東西.
當(dāng)but / except后面跟不定式時(shí),如果but / except前面有實(shí)義動(dòng)詞do或do的其他形式,后面的不定式符號(hào)要省略.如：
In winter the bear does nothing but lie down and sleep. 冬天,熊除了躺下睡覺什么也不干.
It had no effect except to make him angry. 除了惹他生氣外,沒產(chǎn)生任何效果.
五、but for 否定復(fù)合介詞,用在名詞前構(gòu)成介詞短語,意思是“要不是”,等于 without.句子中只要有 but for,該句子必須用虛擬語氣.
But for your help （if you had not helped us）we should not have finished in time.要不是你的幫助,我們就不會(huì)及時(shí)完成.
But for the rain (= If it had not rained) we should have had a pleasant journey.要不是下雨,我們就會(huì)有一個(gè)愉快的旅途的.
六、apart from在不同的上下文中,既有besides的含義,又有except和except for的含義,要根據(jù)上下文來判別.如：
Apart from English, he has a good command of Russian and French. 除英語外,他還精通俄語和法語.（= besides)
He has no interests, apart from his work. 他除了自己的工作外,沒什么興趣愛好.（= except )
It’s a good paper, apart from a few spelling mistakes. 這是一篇好論文,只是有幾處拼寫錯(cuò)誤.（= except for)