我不知道。

Just drop it into a sentence when someone asks a question. You can use it as a standalone answer. You can also add it to the start of a sentence. For example, "I don't know where he is." It works just like English. It is one of the first phrases you should master. It is a total lifesaver when you are feeling overwhelmed.

You can use this in almost any daily situation. Use it when a tourist asks for directions. Use it when your boss asks for a file you haven't seen. Use it when your friend asks what you want for dinner. It is perfectly fine for texting or face-to-face chats. It is the ultimate "get out of jail free" card for beginners.

Avoid using it too bluntly with elders or high-ranking bosses. It can sound a bit dismissive if you don't add a polite "sorry." If someone asks for your opinion, 我不知道 might sound like you don't care. In those cases, try saying "I'm not sure" instead. Don't use it if you actually *do* know but are just being shy. Your Chinese friends want to hear your thoughts!

In Chinese culture, admitting you don't know can be tricky. There is a concept of "saving face" for both parties. Sometimes, people might give a vague answer instead of a direct "no." However, as a foreigner, people expect you to be direct. 我不知道 is seen as honest and helpful. It prevents you from giving wrong directions to a lost person!

You can make it softer by adding 我也不太清楚. This means "I'm not too sure either." If you want to sound very casual, just say 不知道. In the south, you might hear people say it very fast. It almost sounds like one single word. Practice saying it with a slight shrug for maximum effect.