NOTE* I understand this is a normal word that is very translatable, but hear me out. Whenever we get a question we do not know an answer to, we reply with "I don't know," and more simply, "don't know." This is a negative/opposite form of "know" by adding a "don't" in front of it. Similar pattern goes to Japanese, Know - 知る / 分かる Don't Know - 知らない / わからない Where "-らない" acts as a "don't" or "not" Also to Chinese, Know - 知道 Don't know - 不知道 Where "不" literally means "Not" But interestingly in Korean language, Know - 안다 / 알아요 Don't Know - 모른다 / 몰라요 In which the word for "not knowing" has its own independent, distinct word, not a phrase-like word that has a prefix/suffix of negation. Now there are definitely words that define "lack of knowledge" such as "ignorant," but not really used in conversational situations. I hope that was interesting, and I did not know which subreddit to post this. Also, I only know those four languages, so if you guys can argue otherwise please share it.