What it means
نمیدونم (nemidunam) is the spoken Tehrani 1st-person-singular form of “I don’t know.” The formal-written equivalent is نمیدانم (nemidânam). The same vowel shift applies across the conjugation: میدانم becomes میدونم (midunam, “I know”), میداند becomes میدونه (midune, “he/she knows”), and so on through the paradigm. The verb دانستن powers a wide range of basic functions, from “I know what time it is” to “I don’t know if I can come,” so the contraction is essentially unavoidable in real conversation.
How to use it
- نمیدونم چی بگم (nemidunam chi begam) “I don’t know what to say”
- نمیدونم کجاست (nemidunam kojâst) “I don’t know where it is”
- اصلاً نمیدونم (aslan nemidunam) “I have absolutely no idea”
Spoken vs written
Spoken Tehrani: نمیدونم (nemidunam). Formal-written: نمیدانم (nemidânam). The shift from â to u in stressed syllables before n is one of the core sound rules of Tehrani Persian, the same rule that turns خانه into خونه (khune) and نان into نون (nun). Use نمیدانم in essays, formal speech, and official writing. Use نمیدونم in any conversation, with anyone, in any city. There is no situation in casual life where the formal version sounds right. The consequence for learners is steep: a beginner who memorizes only نمیدانم will struggle with native audio, since the spoken form is what fills films, podcasts, voice notes, and street talk almost universally.
Cultural note
Persian conversation often pivots on نمیدونم, since direct “yes” or “no” answers can feel curt. A polite Iranian dodge to a hard question is نمیدونم والا (“I really don’t know”), with the والا signaling sincerity. Pair it with a shrug and a soft smile and you have one of the most-used verbal moves in Tehran. Learners who never adopt the spoken form end up sounding stiff in exactly the conversations where Persian wants to be most relaxed. The phrase also appears in a thoughtful pause register: a speaker says نمیدونم and trails off, signaling they need a moment to think rather than that they truly do not know. Reading that distinction takes practice; it is one of the small skills that separates conversational fluency from textbook fluency.
References
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