If the respondent's reply to your question is "I don't know" , then it implies that his/her understanding of the English language is enough to understand the question. Let's assume that the question is asked to a healthy native English speaker, and that he/she understands the question perfectly.

Another way to look at this question is: All questions can be answered by saying "I don't know". Are there any exceptions to this statement?

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    I'm voting to close this question as off-topic because it is not about the natural properties of languages. You may try Philosophy.SE Jan 19, 2017 at 23:48
  • Or if you're after the kinds of answers that have been given here then you might like to try the Puzzling site.
    – curiousdannii
    Jan 20, 2017 at 5:28
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    I don't know...
    – Travis
    Jan 20, 2017 at 21:12
  • - ' Can you say something ?' ' Do you speak ?'
    – ARi
    Jan 22, 2017 at 13:09
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    Now that I think of it, I suppose there is an advantage to posting questions in the wrong places. Different audiences probably have different ways of looking at things, and differ in their area of expertise. With that in mind, what if someone purposefully posted a question in an unrelated forum? That that generate more creative answers, at the expense of the forum's orderliness.
    – extense
    Jan 23, 2017 at 22:47

4 Answers 4


Based on the criteria of a healthy speaker who perfectly understands the question.

Do you speak English?


Are you awake?

Can you hear me?

Are you able to speak?


"Do you know everything?"

If they say they don't know, they are lying. Even if they argue that they don't know if they don't know that, that just moves the problem to that assertion. So the answer must be either yes or no.

  • But that can say "I don't know", implying Yes but still being a valid language
    – Travis
    Jan 20, 2017 at 21:13

The rules of the game don't require truthful answers: "I don't know" can always be uttered in response to any question. A strict epistemological nihilist (skeptic) must answer all questions with "I don't know": the opposite of such an epistemological affliction, which doesn't have a conventional name but we could call him an omniscientist, can never truthfully reply "I don't know". Similarly, which conjoined with an explanation of Aristotle's first principle of logic, the sentence that ends "and do you agree that those who deny the first principle should be flogged or burned until they admit that it is not the same thing to be burned and not burned, or whipped and not whipped" can't be answered "I don't know".

Perhaps you have in mind that lying, being uncooperative, or being a skeptic, is proof that a person is unhealthy, so maybe you should first define "healthy".

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