Eskimos have 30, 40, 50, n words for snow.
This one is pretty endemic to Canada and the United States and it's plagued with problems. There is no single Eskimo language; there is an Eskimo-Aleut family of languages. None of the languages have an unusual number of words for snow, and most have just a few. Unlike other myths we'll look at which are usually rooted in racism or social bigotry, this myth was probably an innocent misunderstanding of how Eskimo-Aleut languages behave. Eskimo-Aleutian tongues are highly polysynthetic.
In linguistics, synthesis is the ability for a noun to change meanings based on morphemes. The word dog can undergo synthesis and pluralize, becoming dogs thanks to the morpheme -s. Synthesis is rare in languages like English and Mandarin, so we call them isolating languages. German and Japanese are mildly synthetic, meaning they are near the world average use of morphemes. Georgian and Hungarian are highly synthetic. Eskimo languages are polysynthetic, meaning they put Georgian and Hungarian to shame. Polysynthetic languages boast the ability to compound enormous sums of morphemes onto a single noun, so that you can make an entire phrase out of one noun that would normally take an entire sentence in English! Suddenly the Eskimo words for snow just got a lot more interesting.
A classic example from Eskimo-Aleut languages is Yupik's single noun tuntussurqatarniksaitengqiggteuq "he/she had not yet said again that he was going to hunt reindeer" (credit to Wikipedia on how to write that out). It is comprised of the noun stem tuntu- "reindeer" and a series of morphemes (morphemes much like the English plural -s): -ssur- "hunt," -qatar- "going to," -ni- "say," -ksaite- "did not," -ngqiggte- "again," -uq "he," "she." Only the word tuntu- has any meaning on its own, much like dog can have a meaning apart from -s but -s is dependent upon dog.
Polysynthesis is not exclusive to Eskimo-Aleut languages. The phenomenon can be found in Australia, Asia, North and South Americas, Europe, and the Pacific Islands (Oceania). Only in Africa are we missing a polsynthetic tongue, and to be honest, there are many African languages that have not yet been adequately studied.
I hope this journey into myth and synthesis was as interesting for you as it was for me. Picard out.