吹牛

You can use it as a simple verb. If your friend says they are the best gamer in the world, you just say 你在吹牛 (You are bragging). You can also add 皮 (pí - skin) at the end to make it 吹牛皮. It functions the same way. In a sentence, it usually follows the subject directly. You can also use it to describe a person as a 吹牛大王 (a bragging king). It is very flexible and pops up in daily conversations constantly.

Use it when you are with friends, family, or close colleagues. It is perfect for those moments at a restaurant when the bill comes and someone claims they forgot their wallet for the fifth time. Or when a friend says they could easily beat a professional athlete. It is a great way to keep people humble. You can also use it to describe yourself modestly, like saying "I'm not bragging, but my cooking is great."

Avoid this in very formal business meetings or with your boss. Even if your boss is clearly exaggerating their success, calling them out with 吹牛 might get you fired. It is too casual for official documents or serious speeches. Also, do not use it if someone is sharing a genuine, hard-earned achievement. You do not want to be the person who ruins a sincere moment by calling it "hot air."

There are many theories about where this came from. One popular story involves ancient skin rafts used to cross the Yellow River. These rafts were made of inflated sheepskins. Sheep are small and easy to blow up. But a cow? A cow skin is huge. If someone claimed they could blow up a cow skin by mouth, everyone knew they were lying. It became a symbol for making impossible claims.

You will often hear 吹牛皮 (chuī niú pí), which is just a slightly longer version. If you want to be even more casual, you can just say 吹吧你 (Keep blowing/Keep bragging). There is also the term 牛逼 (niú bī), which is slang for "awesome," but be careful—that one is much more vulgar. Stick to 吹牛 for a safe, fun way to tease your friends about their tall tales.