title_body: How could my to be constructed language reflect a culture of carefulness? For a role-playing setting, I want to construct an elven language. The society of these elves strongly values being careful, thinking things through, taking one’s time and preventing mistakes. This is not a recent development but has been that way for centuries.
  
  I feel that the language should somehow reflect their culture of being careful and preventing mistakes — somewhat like the Japanese language mirrors the importance of showing respect to the other party with a wide range of respectful address suffixes, respectful grammatical features and a respectful vocabulary.
  
  In what way could I implement my elves’ carefulness and mistake-preventing ideal in their language?
  
  
  
  As requested in the comments, here is some further elaboration of what I have in mind.
  In cultures, certain behaviour is considered acceptable, certain behaviour is considered well-mannered and other behaviour is considered rude. For example, in Germany coming straight to the point is considered the normal, accepted behaviour while giving white lies is frowned upon to different degrees leading to Germans outright stating what they observe even in other languages in what is elsewhere considered an unfriendly manner.
  
  On the other hand in China, not being able to provide an answer to a question is considered rude so accepted behaviour instead is to provide an answer even if one has no idea if it is true or not. (That is the impression I got from interaction with previous Chinese colleagues.)
  
  In the culture of my elven society, it would be perfectly acceptable and even considered well-mannered to let a deadline pass or let somebody wait in order to perfection a good or a service. On the other hand, providing someone with a flawed product or a not fully thought-through piece of advice would considered disrespectful because one should have taken the time to ensure the error within does not exist. (Such behaviour would be entirely unacceptable in Germany where it is expected for the finished product to arrive five minutes before the deadline.)
  
  A number of common — to them — proverbs would underline this expectation. Maybe something along the lines of ‘the time you lose from a bad result outweighs the gain from finishing quickly’ or ‘even the king will gladly wait for his crown’ etc.
  
  I hope I have made the general idea more clear.
upvoted_answer: My idea on that would be very close to what you suggested yourself: introducing suffixes / prefixes which would indicate the uncertainty of the word.  For instance, let's suppose that your word for "strong" is hariq, your word for "I sit down" is brumo and your word for "house" is niptug, and the word for "in" or "inside" would be bomp.*
  
  Now I would invent some prefixes, such as ar- meaning "with great certainty," no prefix meaning something along the lines of "a certain degree of certitude, but not absolute certainty," (such as, it is supposed that; it is presumed that) and fun, meaning, "a large amount of uncertainty" (such as "we think" or "it appears possible that")**
  
  Now let us suppose that I want to say that I that I sit down in the house, with an extreme certainty that it was a house that I was sitting in, but the fact that I was sitting or that I am actually inside is assumed to be true, though it could be theoretically disproved.  I would say,
  
  arniptug bomp brumo
  
  
  In this fictive language,
  
  funhariq niptug arbomp brumo
  
  
  would mean, "I sit down in a place definitely inside a house which appears to be strong."
  
  Note that these suffixes / prefixes could theoretically be added to any part of speech, or made different for nouns, verbs, adjectives, interjections, etc.
  
  You could also possibly devise a way to make the order of the words show a carefulness about exactly how accurate what is being said is.
  
  * Words invented totally randomly.
  ** Again, randomly selected; more or less prefixes could be used,
   with different definitions.  This is just an example.