Usage note
开心可以用来表达快乐的心情，也可以形容令人愉快的事情。
kāi xīn kě yǐ lái bùgòng biǎo达快乐的 jīngqíng ，yě kě xíngróng róng lèrén wèikào de shìqíng 。
开心 can be used to express a happy mood, and also describe pleasant situations.
Context note
开心常用于描述人们在节日、聚会或做自己喜欢的事情时的感受。
kāi xīn cháng yòng yú miáo shù rén men zài jié rì 、 jù huì huò zuò zì jǐ xǐ huān de shì qíng shí de gǎn jué 。
开心 is often used to describe people's feelings during holidays, gatherings, or when doing things they like.
5 examples
今天天气真好，我们很开心。
jīn tiān tiān qì zhēn hǎo， wǒ men hěn kāi xīn。
The weather today is really nice, we are very happy.
这个礼物让孩子们非常开心。
zhè ge lǐ wù ràng hái zi men fēi cháng kāi xīn。
This gift made the children very happy.
妈妈做的饭菜很美味，全家都很开心。
mā ma zuò de fàn cài hěn měi wèi， quán jiā dōu hěn kāi xīn。
Mom's cooking is very delicious, everyone in the family is very happy.
看到小猫在草地上玩耍，我很开心。
kàn dào xiǎo māo zài cǎo dì shàng wán shuǎ， wǒ hěn kāi xīn。
Seeing the little cat playing on the grass, I am very happy.
听音乐可以让人感到很开心。
tīng yīn yuè kě yǐ ràng rén gǎn dào hěn kāi xīn。
Listening to music can make people feel very happy.
5 mini stories
小明今天收到了生日礼物，他非常开心。妈妈说他也应该开心起来。
xiǎo míng jīn tiān shōu dào le shēng rì lǐ wù， tā fēi cháng kāi xīn。 mā ma shuō tā yě yīng gāi kāi xīn qǐ lái。
Xiao Ming was very happy today after receiving his birthday gift. Mom said he should be happy too.
我们一起去公园玩，大家都很开心。
wǒ men yì qǐ qù gōng yuán wán， dà jiā dōu hěn kāi xīn。
We went to the park together and everyone was very happy.
小红和朋友们一起唱歌跳舞，她们都很开心。
xiǎo hóng hé péng yǒu men yì qǐ chàng gē tiào wǔ， tā men dōu hěn kāi xīn。
Xiao Hong and her friends sang and danced together, they were all very happy.
爸爸带我们去游乐园玩了一整天，全家人都很开心。
bà ba dài wǒ men qù yóu lè yuán wán le yì zhěng tiān， quán jiā rén dōu hěn kāi xīn。
Dad took us to the amusement park for a whole day, everyone in the family was very happy.
妈妈做的蛋糕很好吃，我们都很开心。
mā ma zuò de dàn gāo hěn hǎo chī， wǒ men dōu hěn kāi xīn。
Mom's cake was very delicious, we were all very happy.
Mini dialogue
生日快乐
A
生日快乐！你今天开心吗？
Shēngrì kuàilè! Nǐ jīntiān kāixīn ma?
Happy birthday! Are you happy today?
B
很开心，谢谢你的礼物！
Hěn kāixīn, xièxie nǐ de lǐwù!
Very happy, thank you for the gift!
一起玩耍
A
我们一起去公园玩吧。
Wǒmen yīqǐ qù gōngyuán wán ba.
Let's go play in the park together.
B
好啊，和你一起玩我很开心。
Hǎo a, hé nǐ yīqǐ wán wǒ hěn kāixīn.
Great, I am very happy to play with you.
Related words and contrasts
similar
快乐
kuài lè
joyful
A common synonym for happy, often used in songs and stories.
opposite
难过
nán guò
sad
The feeling when something bad happens, opposite of happy.
similar
高兴
gāo xìng
glad
Very similar to 开心, used when you feel good about something.