你应该好好理解一下，have和have got到底是AE 还是BE英语，弄清楚了，你就不会迷糊了，就像别人问你，have you got any shoes like these ?如果你回答：no，i don't have .本身就是个逻辑上的错误。如果有人问你do you have any shoes like these?你如果回答：no，i have not （got);（或者 i haven‘t (got)）。也是不对的。明白我说的意思了吗？理解一下助动词，或许能让你茅塞顿开。只有在表达“有”的概念时，have 和have got 才有相同意思，不过只是时态上的不同而已，have是美国人喜欢使用的，have 是有实际意义的动词，表达是现在时态，而have got 是英国人习惯表达方法，have是helping verb，所强调是现在完成时中，从过去到现在一直持续的概念。例如 i have a pen。和i ‘ve got a pen。这是美国人和英国人在表达方法上的不同。英国人在说话的过程中不知不觉中更强调这个钢笔是从过去一直到现在属于他，而在未来就一定了。美国人则恰恰相反，没有这个观念。 另外有很多关于吃、喝、生病等固定的表达，例如：i have a headache。千万不能根据have=have got 的逻辑进行等同。如果把i often have a headache 说成：i often have got a headache，那就是最致命的错误了，因为所表达的概念完全不同。千万不要把中学老师告诉你：have 是什么意思呢，老师告诉你，他是“有”的意思。完全是在误人子弟。因为一旦你建立起have 就是“有”的之后，你的思维就被固化了，遇到have就是“有”不会有别的意思，连最起码吃喝生病的意思都被无意识的加上了有的观念，更别提他是helping verb了。

carven, "I haven't" is and older form with the same meaning as "I don't have". It is not a short form for "I haven't got" which is another way to express possession. "I haven't" seems old-fashioned to some but (in Canada) you still hear it: -I haven't a clue. -I haven't a penny to my name. -I haven't the time to explain all that to you. -I haven't any reason to be mad. -I may be willing to travel, but I haven't a passport yet. ------ -I haven't a particle of confidence in a man who has no redeeming petty vices. - (Mark Twain, American writer) -I haven't any right to criticize books, and I don't do it except when I hate them. I often want to criticize Jane Austen, but her books madden me so that I can't conceal my frenzy from the reader; and therefore I have to stop every time I begin. Every time I read Pride and Prejudice I want to dig her up and beat her over the skull with her own shin-bone.-- Mark Twain 1898 The full form --I have not-- is rarely used in speech. You might find it in formal writing or used for emphasis as Genco stated above.

"I have not a pen" is very uncommon in modern speech. You'd only use this form to give a dramatic or mock-Old-English effect. The meaning is closer to "I have no pens at all!" When you use "have not", it is more commonly followed by an action to create present perfect form: "I have not used a pen since 1967." Using it to indicate non-possession is less common but still used, viz. Denis' examples using "haven't". "I don't have a pen" is the standard accepted phrase, to mean you are without a pen. "I do not have a pen" is used for slight emphasis.

我的理解是have是动词，表示否定时候前面加don't，因为后面直接加not的一般是系动词，比如is not , am not , are not. have not 是表示已经完成的否定，例如上面一位的回答中，have表示的是完成时，而真正的动词是get， 回答have not 实际是完成时的否定 并且强调我没有拿。 谢谢 此处是我的理解

There is no difference, but "I have not a pen" is very unusual and I never heard it. If somebody asks you "Do you have a pen?" you could answer "I don`t have a pen." Well, if somebody says to you "You have got my pen!! Give it back!" you could answer "I have not!" I hope this helps a little bit. But maybe a native english speaking will answer here, too. So be patient :) yours sincerly Genco