Is there a natural language which is known not to follow Zipf's law? I'm interested to see if it's really universal.
This is what Zipf's law states:
Zipf's law states that given some corpus of natural language utterances, the frequency of any word is inversely proportional to its rank in the frequency table. Thus the most frequent word will occur approximately twice as often as the second most frequent word, three times as often as the third most frequent word, etc.
Edit - To clarify a bit - imagine that you could snoop on every conversation held by native speakers everywhere, in every context, over the course of one year, and record every word, and then count the words occurring, and calculate their frequencies, would they deviate from Zipf's law? Now, we can't do that in reality, but for languages with a substantial written corpus, we can have a broad enough sample.