I Don't Know (모르겠다)

A representative Korean expression revealing uncertainty in knowledge and judgment, connected to epistemology, pragmatics, and discussions of AI uncertainty.

I Don't Know (모르겠다)

Overview

“모르겠다” (I don’t know) is a representative expression in Korean that reveals that one’s knowledge or judgment is not settled. It does more than simply report the absence of information; it performs various pragmatic functions, including soft refusal, suspension of judgment, modesty, and polite disagreement. Recently, it has drawn renewed attention in connection with discussions of abstention—whether artificial intelligence can say “I don’t know.”

Main Content

Etymology and Grammatical Structure

“모르겠다” is formed by combining the stem “모르-” with the pre-final ending “-겠-,” which marks conjecture or supposition, and the final ending “-다.” The intervention of “-겠-” creates a more subjective and softened nuance than “모른다” (don’t know), and strengthens its metacognitive character, in that the speaker monitors and reports on their own current state of awareness. Honorific forms are realized as “모르겠습니다” and “모르겠어요,” while the casual form is “모르겠어.” When used as a response to a negative question, pragmatic hedging expressions such as “모르겠는데요” are sometimes added.

Pragmatic Functions

First, it announces the absence of information. It is used most directly when one does not know the answer to a question. Second, it functions as a soft refusal. When it is burdensome to reject the other person’s request outright, “그건 좀 모르겠습니다” (I’m not so sure about that) serves as a buffer. Third, it expresses suspension of judgment. It conveys an attitude of postponing a conclusion until sufficient information has been gathered. Fourth, it serves as polite disagreement. “그렇게 하는 건 좀 모르겠어요” (I’m not so sure about doing it that way) lowers the risk of damaging the relationship compared with explicit disagreement. Fifth, it is sometimes used as an interjection expressing frustration or admiration, as in “모르겠다, 정말” (I don’t know, really).

Sociocultural Context

Korean speakers often use “모르겠다” as a buffer in interpersonal relationships within norms of face, nunchi (social awareness), and modesty. By contrast, the English “I don’t know” tends to be accepted as a relatively more direct statement of the absence of information, so the strategy of expression choice differs even in the same situation. Studies comparing it with the Japanese “Wakarimasen (分かりません)” also observe differences in the degree of negative certainty and in politeness strategies.

Epistemology and Psychology

“Knowing that I do not know” has been regarded as the starting point of knowledge since Socrates. In cognitive psychology, it is connected to metacognitive ability—the capacity to assess one’s own state of knowledge—and is discussed as a counter-case to biases such as the Dunning–Kruger effect, in which lower skill is associated with overestimation of oneself. The phenomenon in which confidence and accuracy diverge is formalized in decision theory as the problem of “calibration.”

Meaning in Education and Learning

A classroom atmosphere in which one can say “모르겠습니다” (I don’t know) is a key indicator of a questioning culture. The moment of admitting that one does not know becomes the starting point of learning, and a body of research has accumulated showing that environments in which errors are not hidden promote conceptual understanding. Conversely, when shame or evaluation pressure is high, students choose guesswork answers or fall silent.

Recent Trends

The biggest change in 2024–2025 is that “모르겠다” has become a reliability indicator for artificial intelligence, beyond a human language habit. As the “hallucination” problem—in which large language models plausibly generate false content—has come to the fore, research on “abstention,” “selective prediction,” and “uncertainty quantification”—training models to withhold answers or say “I don’t know” when they cannot be certain—has surged. In areas where the cost of wrong answers is high, such as medicine, law, and finance, designs based on retrieval-augmented generation (RAG), evidence citation, and confidence-threshold-based refusal to answer are becoming standard. In Korean LLM evaluation as well, attempts to measure “the ability to correctly say that one does not know” as a separate metric are increasing. In educational settings, “epistemic humility” education—critically verifying the confident wrong answers of generative AI—is being emphasized, and prompt literacy such as “asking AI to say I don’t know” has emerged as a new basic skill. At the same time, the adverse effect of excessive “모르겠다” being seen as evasion of responsibility is also being discussed, and normative research on the appropriate frequency and context of expressions of uncertainty is underway.