改天吧。

You usually place it at the end of a sentence. Or, you can use it as a standalone response. If a friend asks you to grab hotpot, just say 改天吧. It sounds natural and effortless. You don't even need to provide a long excuse. The phrase itself implies you have other things going on. It is short, punchy, and very common in daily life.

Use it when you are genuinely busy. Use it when you are tired and just want to go home. It works perfectly with friends, colleagues, or even your boss. It is great for texting when someone sends a last-minute invite. At a restaurant, if a server offers a dessert you don't want, it works there too. It is the 'Swiss Army Knife' of polite refusals.

Do not use it for urgent or serious matters. If your doctor asks to see you, don't say 改天吧. Avoid using it if you actually want to set a specific time. This phrase is intentionally vague. If you use it with a romantic interest too often, they might think you are ghosting them. Use it sparingly if you actually want the person to keep asking you out.

Chinese communication often prioritizes 'saving face' for both parties. Giving a direct 'no' can make the other person feel rejected. 改天吧 provides an 'exit ramp' that preserves the friendship. It is part of a broader social dance called 'polite refusal.' Interestingly, if someone says this to you, don't always expect a follow-up. Sometimes it really means 'never,' but in the nicest way possible.

You can say 我们改天吧 to make it more inclusive. If you want to sound more certain, try 改天请你吃饭 (I'll treat you another day). Adding 下次吧 (xià cì ba) is a very similar alternative. If you are in a rush, a quick 改天，改天 works well. These variations help you navigate different levels of social pressure with ease.