What is Zipf's Law and how to use it to your advantage when learning a language?
I have provided some links at the bottom of this post that explain in detail what Zipf's Law is. I will try to summarily explain this phenomenon in my own words. A good way to put it is to call it the 20-80 rule. When applied to language it states that top 20% of the most frequently used words in a corpus large enough will make up 80% of it.
To make it clearer, say a novel contains 5000 different words. According to the rule, 80% of the novel will be the most frequently used 1000 words. The ratio can of course change but the principle stands. Oxford says, for example, that the most frequently used word in English "the" makes up about 6% of it. One of every 16 words in English is "the".
How can you use this to your advantage ? It can help you better target your efforts. By mastering for example the most commonly used say 50 verbs, 50 adjectives and 1000 words together with the basic grammar rules you can get quite a hang of that language and communicate with people.
Here is an blog post about the same subject. It is about how Pareto principle (and Zipf's law) relates to language learning and how many words you should learn in your target language to understand most of all the conversations and texts spoken or written in that language. http://www.lingholic.com/how-many-words-do-i-need-to-know/