都行。

Use it as a standalone answer to a 'this or that' question. If someone asks, 'Coffee or tea?' you just say 都行. You can also put it at the end of a sentence. For example, 'Friday or Saturday, 都行.' It is incredibly short and punchy. You don't need complex grammar to sound like a native here. Just drop it and let the other person decide.

You can use this in almost any casual setting. Use it at a restaurant when a friend asks what to share. Use it when texting to decide on a movie time. It is great for being a low-maintenance guest. It also works in low-stakes office situations. If a colleague asks if you want to meet at 2:00 or 3:00, 都行 shows you are flexible. It makes you seem like a very easy person to work with.

Avoid this if a decision actually requires your specific input. If your boss asks for your professional opinion on a strategy, saying 都行 might make you look lazy or indifferent. Also, be careful using it too much with a romantic partner. If they ask where you want to eat for your anniversary, 都行 can sound like you don't care about the date. Sometimes, 'I don't care' is the wrong vibe. Use it for logistics, not for showing passion.

Chinese culture often values harmony and 'giving face.' By saying 都行, you are letting the other person take the lead. It is a way to avoid conflict or appearing too demanding. However, there is a famous 'Buddhist youth' (佛系青年) subculture in China. These young people use 都行 to express a zen, 'whatever happens, happens' attitude toward life's stresses. It is a linguistic shield against the high-pressure modern world.

If you want to sound even more casual, try 都可以 (dōu kě yǐ). It means exactly the same thing. If you are feeling extra indifferent, you might say 随你 (suí nǐ), which means 'up to you.' For a slightly more formal 'either is fine,' you could use 两个都可以. But for daily life, 都行 is the undisputed king of flexibility. It is the Swiss Army knife of Chinese responses.