Have no idea means to know nothing at all about something: I have no idea where he is. The phrase You have no idea how… means “you can't imagine how…” and makes a feeling stronger: You have no idea how tired I am.
Want to remember have no idea?
Write a sentence — we'll show the mistakes right away and suggest how to say it more naturally.
The check is taking longer than usual. Your feedback will appear here automatically.
have no idea + what/where/how/why…; have no idea (that) + clause; have no idea about + noun; You have no idea how + adjective/clause
- I have no idea where I left my keys this morning.
- She had no idea that the meeting had been moved to Monday.
- You have no idea how much I needed this holiday.
What changed
First versionI don't have no idea where the station is.
RevisionI have no idea where the station is.
The sentence is negative, so don't can seem necessary. But in English one negative is enough: no already makes the whole sentence negative. With don't, you get a double negative, which is a mistake in standard English. Don't was removed. You can also say I don't have any idea, but then no changes to any.
I have no idea sounds stronger than I don't know: not just “I don't know” but “I haven't got a clue”. In conversation, people often reply with just No idea. In British English, I've got no idea is also common: I've got no idea what time it is.
Your turn
I've checked the timetable twice, but I still ___ when the last train leaves.
Show the answer
have no idea — The speaker has checked the timetable twice and still doesn't know when the last train leaves, so have no idea fits. Don't have no idea has two negatives, and that isn't standard English.
Write about a time when you had no idea what to do. Say what the situation was and how you found a solution.
When my laptop suddenly stopped working the night before an exam, I had no idea what to do, so I called my cousin, who fixes computers.
Learn to use new words without mistakes
Write phrases with the words you are learning. LetsWords shows mistakes in usage and grammar, suggests corrections and explains them, and review helps the words stick.