哪里，哪里 - Not at all, not at all

Here's another observation about Chinese people. It's a common one made by many foreigners here but it's a very lovable one and it's always worth saying again.
While the Chinese themselves are very humble and reluctant to accept any praise they are very eager to deal it out. The most common example is that of the foreigner that just manages to pronounce the "ni hao" (hello) reasonably correctly. This will most likely earn him a praise of "oh, your Chinese is so good" or "you speak almost as good as Chinese people".
Now, while these days in Western countries it is common to acknowledge a compliment with a polite nod and a "thank you" it is considered polite in China to completely deny the compliment. Still, in areas where foreigners are common people have got used to Westerners' ways of saying "thank you". However, if you counter their compliment with an appropriate "bu hao, bu hao" (not good, not good) or "nali, nali" (not at all, not at all) you're likely to get even more praise for knowing this cultural detail. This happened even from our teachers and even though this habit is commonly mentioned in every textbook. If you then praise your opposite's English or other language proficiency this can lead to interesting exchanges of mutual praising and denying.

This habit and its consequences are nicely illustrated in a (Chinese) joke, which goes like this:
A foreigner who is just learning Chinese is meeting his Chinese friend and his wife. In class the foreigner has learnt that you should praise, so for example praise your friend's wife. So he says: "你老婆很漂亮. (Your wife is very pretty.)"
The Chinese friend, of course being humble, replies: "哪里,哪里. (not at all, but can also mean a question of "where, where abouts")"
So, the foreigner, misunderstanding, responds by pointing at the important parts of the lady's anatomy commenting: "这里漂亮,这里也漂亮... (here she's pretty, here she's also pretty)"

Of course, this habit eventually leads to the fact that you don't take any compliments seriously anymore. I just know my Chinese level is not that good. Still, in other - especially English-speaking - countries people just take for granted that your speak - or try to speak - their language. It's nice to have your ego stroked once in a while.