认真

Using it is super simple. You can describe a person by saying 他很认真 (He is very serious/earnest). You can also use it to describe how someone does an action. Just add 地 (de) after it, like 认真地学习 (studying earnestly). It works as both an adjective and an adverb. It is a very flexible 'Lego' piece in your Chinese sentences.

Use it when you see someone working hard at the office. Use it when a friend is listening intently to your problems. It is great for praising kids who are doing their homework. If you are confessing your feelings to someone, you definitely want to use it. It shows you aren't joking around with their heart.

Don't use it to mean 'serious' as in 'stern' or 'scary.' If a teacher has a 'serious face,' that is usually 严肃 (yánsù), not 认真. Also, don't use it for 'serious' medical conditions. If someone is 'seriously' ill, that is 严重 (yánzhòng). Using 认真 there would sound like they are being very focused on being sick, which is just weird.

In Chinese culture, being 认真 is a top-tier virtue. It is deeply rooted in the idea that persistence and attitude matter more than raw talent. There is a famous saying: 'The world fears only those who are 认真.' It implies that if you are truly earnest, you can overcome any obstacle. It is the secret sauce to success in school and work.

If you want to ask if someone is joking, ask 你是认真的吗? (Are you serious?). If you want to tell someone to snap out of it and focus, say 认真点儿! (Be a bit more serious!). You might also hear 认认真真, which is just a doubled-up, cuter way to emphasize the effort. It makes the 'earnestness' feel even more intense and deliberate.