I don't know

• (US) IPA^(key): [ɑɪ̯ ɾoʊ̯(ʔ)t̚ noʊ̯]

  • Audio (Mid-Atlantic)

    (file)

• (tonal) IPA^(key): [ə˦˩˦], [m˦˩˦]

• Audio (UK)

  (file)

• Rhymes: -əʊ

I don't know

1. A phrase used in response to a question or command in which the target person does not know the answer to or how to respond.
   • 1982,You Can't Do That on Television, Nickelodeon, season 3, episode 11:

     Mr. Schidtler: Does anybody here have any idea why "Inestine" was regarded as a great scientist? Kevin?

     Kevin: Oh, uh, I don't know.

2. A reason and common excuse used to state that a person is unclear of why something did or did not happen, or is or is not the case.
   • 1984, Alasdair, You Can't Do That on Television, Nickelodeon, season 5, episode 24:

     I don't know why Blip just shuts off the power and then blames it on the weather.

3. A phrase used to indicate that one is speculating (often used sarcastically when stating the obvious).

   Maybe you could, I don't know, directly talk to her about it instead of complaining to me for once?

• I know

• dunno
• iunno