簡單來說, 如果句子裡有 all, every, no, everything, nothing, everyone, no one, nowhere, whole 等字時, except 和 except for 是通用的 例: Everyone was there except (for) John. 但如果沒有上述那些字時, 就要用 except for 而不能用 except 例: It was a good plan except for the people involved. (O) It was a good plan except the people involved. (X) 另外, 在像 do 的特殊句型裡, 後面要接原形動詞時, 只能用 except 而不能用 except for 例: She does nothing except complain all day. (有關 do 的特殊句型請見 how-to-use-English-word-do-did-has-done )