我以前在几个论坛写过一篇 “cannot is one word”, 写得很乱。(例如：
http://www.rainlane.com/dispbbs.asp?boardid=11&id=17484&star=1#12446 )看多人看了都莫明其妙。所以从新写过一篇。
(1)
Cannot is one word, in British, American, and Canadian English. (Probably the same for Australia and New Zealand) “Can not” is only for emphasis, and is rarely used.
Cannot 是一个词, “can not”只是用在强调语气, 而且非常少用“. (In the cartoon below, the first cannot is a negative of can, and the second can+not is for emphasizing can and not.)
(click on image to enlarge.)
引自：漫画学英语 # 79
http://www.rainlane.com/dispbbs.asp?boardid=27&star=11&replyid=11556&id=6499&skin=0&page=1(2) Cannot 是一个词. 金山词霸”上说，cannot 在美式英语是两个词 (can not)
是不对的。 Some other dictionaries define cannot as “cannot=can not” is very misleading. They wanted to say “cannot” has the meaning of “can not”, but the “equal sign” gives people the incorrect impression that the two are the same. 有些词典把 cannot的定义写成 “can not”. 原意是说 cannot 的意思是 can+not. 但这样写法很容易使人误解 “cannot” 与 “can not” 是一样。 Webster 伟氏大词典上的定义，很使人误会。(见 #3)
(3) Even in the Webster, the definition is misleading，as can be seen from the following complaint
甚至在伟氏大词典，解释也令人有所误会。如以下有专家的批平：出自 Source:
http://www.languagehat.com/archives/000876.php(这个英语专家(编辑)说 Webster 词典上把“cannot” 的定义写成“can not” 就是令人误解。他说这是” a lousy definition “。这定义使读者以为 can not is 对的。所以会有这么多人出错.)
A fellow editor discovered that somebody had inserted a space into cannot, and wanting to back up his insistence that it had to be one word, he turned to his brand-new Webster's. Imagine his horror, and mine when I saw it, at finding that the definition for the word was "can not."
This is appalling for two quite distinct reasons: from a copy-editing point of view because it implies that cannot and can not are interchangeable, and from a lexicographical point of view because it's a lousy definition. The definition of cannot should be either "the negative form of can" (as the AHD has it) or a periphrasis like "is not able to."
(4) If you don’t believe that cannot is one word in both English and American English, you can verify what I say by going to
http://www.google.com and enter the search phrase “cannot is one word.” 你若不信。可往
http://www.google.com 上搜索“cannot is one word”，便会其见到很多英国，美国，加拿大，大学英语系的网页上警告它们的学生： “cannot is one word.”
(4b) If you read the on-line Webster 伟氏大词典, you will find them saying cannot can be one word or two. What they do not mention is that cannot is one word when it is for the negation of can, and two words only when it is for emphasis.
(5) 母语人士也有这个错误。你只要去
http://www.google.com 搜索 “cannot is one word”, 便会看到很多很多英国，美国，加拿大，大学英语系的网页上警告它们的学生不要把 cannot 写成两个词：“ cannot is one word.”
Some people may say, “I saw on Chat rooms, native speakers using “can not”.” Native speakers are not always correct. That is why there are so many warnings in university web pages that “cannot is one word.” 你或会说” 我在聊天室碰到有些老外用 can not.” 不是每个母语人士都说十全十美的母语。看看本人写中文时了多少别字。
(6) 近来网上写作求改的学生作文上，把 cannot 写成两个词越来越多。不知是金山词霸的影响，还是因为在”四，六级背诵范文“上有个 “can not” 的错误没有更正以至度人误解 . 要知道网上的范文不是全是老师或专家所写，多是修改过一下的好的学生作文。所以只能作为参考一下，不应用背诵。
(7) 以下语法专家所说的话，可用来做这贴子的总结。
引自雨巷英语角贴子 “Fine Points in English”， 第 35 楼
http://www.rainlane.com/dispbbs.asp?boardid=11&star=4&replyid=4614&id=10179&skin=0&page=1 上的参考：
Reference 1: (参考一 )
http://www.grammarmudge.cityslide.com/board/board_topic/1268580/58941.htmQuestion: Are there different usage rules for "can not" vs. "cannot?"
Answer: Indeed there are. What we should use when we mean "are unable to" or "are not permitted to" is one word: cannot. This is the word that we contract when we write "can't." It is a common error to separate "can" and "not."
The American Heritage Dictionary is quite clear on this point: cannot is the negative form of the word can. … To all my fellow nitpickers out there: I am fully aware that the two-word construction "can not" is often used where the opposite of "can" is intended. Despite the ubiquity of this usage, it is still an error.(
须然到处到有人把cannot写成两过词，但这仍然是错误的)
