One of the more interesting facets of No Man's Sky is learning the alien languages, one word at a time, so that you eventually understand what the extraterrestrials (or perhaps you're the extraterrestrial) are saying. And through a semi-exploit in a dialogue tree, I've discovered that the alien language in my game so far has a little over 400 words.
In my playthrough, the alien race on my starting planet are the Korvex, a scientifically-driven species who are outfitted with suits and consider me to be a fairly insignificant but still fascinating lifeform. Luckily, I've explored enough facilities on the planet to gain their respect, and by the time I met Chemist Entity Niem in the screenshot above, I was already a "Traveler of the Atlas."
Because of my standing, Niem was ready to provide me with isotopes and fuel at my behest; that is, Carbon, which is exactly what I need to speak to Niem again. In between the Carbon gifts, I could ask Niem to provide me with one translated word. So let the dialogue loop begin!
After about six hours of grinding, I finally got the surprising message that I could not learn anything new from Niem. Whew! Six hours may sound like a long time, but scouring the world for knowledge stones and monoliths would take much longer. Checking the Journey tab for milestones (screenshot below), the final tally of words I learned came to 408. Now, I believe 3 of the words were a part of a separate alien language, so I can believe that the Korvex language has about 405 words in all.
An important caveat: This is based on the English language. The number of words in the alien language likely depends on the native language of the game, and how many of those words are used as text in the game.
Learning all the words in the language not only helps in understanding the NPCs and the story, as vague and freeform as it is, but it can also help in inputting the right passcode in certain alien facilities based on the clues given in the alien language.
I'll update this feature if I learn anything new about the alien languages in No Man's Sky.
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