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What does IDK mean?

Say iteye-dee-KAY/ˌaɪ.diːˈkeɪ/abbreviation

Stands for
  1. II
  2. DDon’t
  3. KKnow

A short, informal way to write "I don’t know."

Written by the Second Language TeamWritten

IDK is short for I don’t know [1]. People use it in text messages, group chats, and social media comments. It can be a quick answer by itself or the start of a longer sentence, like "idk what to do about it."

Say it letter by letter: eye-dee-KAY [2]. Out loud, most people just say "I don’t know" and keep IDK for typing. The Oxford Learner’s Dictionary labels it informal and also writes it in lowercase, idk [2]. It is not rude, but it is too casual for emails to teachers, bosses, or clients.

Word stats

How casual
Informal, but fine with friends, classmates, and most people you text. Not for formal writing.
OK at work
Okay in a quick chat with a coworker you know well. With your boss or a client, write "I’m not sure."
Grandma-safe
Not rude, so it is safe with relatives. A one-word "idk" to your mom, though, can sound like you are not even trying.
Cringe risk
Very low. IDK is so normal that nobody notices it.
Freshness
Steady. About as many people look it up as last year. People never stop not knowing things.

Spotted in the wild

Group chat · Friday, 7:15 pm
  1. Jinok where are we eating
  2. Sofiaidk
  3. Marcoidk either
  4. Youwe can’t ALL be idk 😭 tacos?
  5. Sofiatacos 🌮

What it means here: Everyone says "I don’t know" until someone finally picks a place.

Text with Dad
  1. DadWhen will you be home?
  2. Youidk, maybe 9?
  3. DadWhat does idk mean?
  4. YouI don’t know
  5. DadThen ask someone who does 🙄

What it means here: You are not sure what time you will be home. Then your dad thinks "I don’t know" is your answer, not the meaning of idk.

Comments on a video
  1. nina.bakesidk how, but my cat learned to open the fridge
  2. leo_kidk whether to be scared or impressed
  3. nina.bakesboth. definitely both

What it means here: Here idk starts a longer sentence: "I don’t know how" and "I don’t know whether."

How to use it

  • idk (as a full answer)A: who won the game? B: idk, I fell asleep.
  • idk + what / how / if / why…idk what to wear tonight.
  • idk, + a guessidk, maybe around 8?
  • idk about…idk about that plan, it sounds expensive.
  • idk lol / idk 🤷 (to sound relaxed)idk lol, ask Sam.

Don’t say it like this

  • Sounds offI idk what to do.

    Say thisidk what to do.

    The I is already inside IDK. Writing it twice is like saying "I I don’t know."

  • Sounds offShe idk the answer.

    Say thisShe doesn’t know the answer.

    IDK always means "I" don’t know. For other people, write the full words.

  • Sounds offSaying it as one word: "ID-ik"

    Say this"eye-dee-KAY", or just "I don’t know"

    IDK is said letter by letter. In speech, most people simply say "I don’t know" or "dunno."

  • Sounds offHi Ms. Park, idk when the essay is due.

    Say thisHi Ms. Park, could you tell me when the essay is due?

    IDK is informal. In emails to teachers, bosses, or clients, write full sentences.

IDK or not?

Is each of these IDK? Pick an answer to find out.

  1. Your friend texts, "what time does the movie start?" You have no idea, so you reply, "idk, let me check."

  2. Your manager emails to ask when your report will be ready. You reply, "idk."

  3. You comment on a friend’s food photo: "idk how you always find the best places."

  4. In a job interview, they ask about your biggest weakness. You smile and say, "idk!"

The IDK family

  • IDCI don’t care.Looks almost the same as IDK. Sends a very different message to the friend asking where to eat.
  • dunnoA casual spoken way to say "I don’t know."What IDK sounds like when it leaves the phone and opens its mouth.
  • IDEKI don’t even know: you are very confused or surprised.IDK after a very long day.

Where it came from

  1. By 2002Grammarly says idk had become part of text speak by at least 2002 [3]. No source names who typed it first.
  2. TodayIDK is one of the most common texting abbreviations, in group chats, comments, and every "where should we eat?" conversation.

Is IDK rude?

IDK is not rude by itself. Like "I don’t know" said out loud, it can sound friendly or cold. The words and emoji around it set the tone.

MessageHow it sounds
idkShort. It can sound bored, or like you don’t want to talk.
idk 🤷Relaxed and friendly. You really don’t know.
idk, maybe 7?Helpful. You are not sure, but you give a guess.
IDK!!Stressed. Please stop asking.

IDK and idk mean the same thing. Grammarly notes that capital letters are optional in casual writing [3]. If a one-word idk might sound cold, add a guess, a question, or an emoji.

Sources

  1. IDK Definition & MeaningMerriam-Webster
  2. IDK abbreviation - Definition, pictures, pronunciation and usage notesOxford Learner’s Dictionaries
  3. What Does "Idk" Mean?Grammarly, updated November 20, 2023

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