Usage note
却表示转折。
què biǎo shì zhuǎn zhé。
Yet means contrast.
Context note
却常放在句子中间，表示和前面不同。
què cháng fàng zài jù zi zhōng jiān， biǎo shì hé qián miàn bù tóng。
Yet often appears in the middle of a sentence to show contrast.
5 examples
他想去，却没时间。
tā xiǎng qù， què méi shí jiān。
He wanted to go, but he had no time.
天气很好，却很冷。
tiān qì hěn hǎo， què hěn lěng。
The weather is nice, but it is cold.
我记得，却说不清。
wǒ jì de， què shuō bù qīng。
I remember it, but I cannot explain it clearly.
她笑了，却没有说话。
tā xiào le， què méi yǒu shuō huà。
She smiled but did not speak.
大家都来了，他却没来。
dà jiā dōu lái le， tā què méi lái。
Everyone came, but he did not.
5 mini stories
我很想去，却要写作业。
wǒ hěn xiǎng qù， què yào xiě zuò yè。
I really wanted to go, but I had homework to do.
他看起来很忙，却还是来帮我。
tā kàn qǐ lái hěn máng， què hái shì lái bāng wǒ。
He looked busy, but he still came to help me.
天气很暖，却下起雨来。
tiān qì hěn nuǎn， què xià qǐ yǔ lái。
The weather was warm, but then it started raining.
老师说很简单，却有人做错了。
lǎo shī shuō hěn jiǎn dān， què yǒu rén zuò cuò le。
The teacher said it was easy, but some people still got it wrong.
我以为会很难，却发现不难。
wǒ yǐ wéi huì hěn nán， què fā xiàn bù nán。
I thought it would be hard, but it turned out not to be.
Mini dialogue
找东西
A
我找了半天书包，却没找到。
Wǒ zhǎole bàntiān shūbāo, què méi zhǎodào.
I looked for my backpack for a long time, but I didn't find it.
B
它就在椅子上，你却没看见。
Tā jiù zài yǐzi shàng, nǐ què méi kànjiàn.
It's right on the chair, yet you didn't see it.
天气变化
A
早上很暖和，现在却变冷了。
Zǎoshang hěn nuǎnhuo, xiànzài què biàn lěngle.
It was warm in the morning, but now it has turned cold.
B
是啊，我带了一件外套，你却只穿了短袖。
Shì a, wǒ dàile yī jiàn wàitào, nǐ què zhǐ chuānle duǎn xiù.
Yes, I brought a jacket, but you only wore a short-sleeved shirt.
Related words and contrasts
similar
但是
dànshì
but; however
但是 is a common word for 'but', while 却 is often used inside a sentence for contrast.
similar
可是
kěshì
but; however
可是 is another way to say 'but', similar to 但是.