1. “就” can be used with hypothetical conjunction to indicate an assumption, which is often used in some certain complex sentence patterns.
e.g.
如果……,就……
如果今年不忙,我们就出国旅行。(Rúguǒ jīnnián bù máng, wǒmen jiù chūguó lǚxíng.) If it is not busy this year, we will travel abroad.
……的话,就……
天气好的话,我们就一起去购物吧!(Tiānqì hǎo dehuà, wǒmen jiù yìqǐ qù gòuwù ba!) If the weather is good, let’s go shopping together!
既然……,就……
既然你想学习外语,就学习汉语吧。(Jìrán nǐ xiǎng xuéxí wàiyǔ, jiùxuéxí hànyǔ ba.) Since you want to learn a foreign language, learn Chinese.
要是……,就……
要是你想学习汉语,就学吧!(Yàoshi nǐ xiǎng xuéxí hànyǔ, jiù xué ba!) If you want to learn Chinese, just learn it!
只要……,就……
只要你愿意,我就马上过来见你。(Zhǐyào nǐ yuànyì, wǒ jiù mǎshàng guòlái jiàn nǐ.) As long as you want, I will come to see you right away.
2. “就” can be used to strengthen the tone of the sentence. It indicates something happened earlier or faster than expected, already.
e.g.
经理今天七点就到公司了。(Jīnglǐ jīntiān qī diǎn jiù dào gōngsīle.) The manager arrived at the company at seven today.
我们小时候就认识,已经是二十多年的老朋友了。(Wǒmen xiǎoshíhòu jiù rènshi, yǐjīng shì èrshí duō nián de lǎo péngyǒule.) We have known each other when we were young, and we have been friends for more than 20 years.
这个语法他学一遍就懂了。(Zhège yǔfǎ tā xué yíbiàn jiù dǒng le.) He has already understood this grammar after learning once.
这条路我走一遍就记住了。(Zhè tiáo lù wǒ zǒu yíbiàn jiù jìzhù le.) I remember this path after walking it once.
“就” is used to emphasize that something is truly so and cannot be changed.
e.g.
A:这是你家?(Zhè shì nǐ jiā?) Is this your home?
B:对,这就是我家。家里就只有我一个人。(Duì, zhè jiùshì wǒjiā. Jiālǐ jiù zhǐyǒu wǒ yīgè rén.) Yes, this is my home. I’m the only one at home.
A:你知道超市在哪吗?(Nǐ zhīdào chāoshì zài nǎ ma?) Do you know where the supermarket is?
B:超市就在我家旁边。(Chāoshì jiù zài wǒjiā pángbiān.) The supermarket is right next to my house.
3. “就” can be used to define the extent, and scope, beyond which there is nothing else.
Subject + 就 + Verb
Subject + 就 + Noun
e.g.
我们家就他会说中文。(Wǒmen jiā jiù tā huì shuō Zhōngwén.) At our home, only he can speak Chinese.
这个城市就这一个学校愿意让你去上学。(Zhège chéngshì jiù zhè yígè xuéxiào yuànyì ràng nǐ qù shàngxué.) Only this one school in this city allows you to let you go to school.
我就拿了一支笔,没拿别的东西了。(Wǒ jiù nále yì zhī bǐ, méi ná bié de dōngxi le.) I only took a pen and nothing else.
上个月我们就赚了三百块钱,生意太差了。(Shàng gè yuè wǒmen jiù zhuànle sānbǎi kuài qián, shēngyì tài chàle.) We only made 300 yuan last month, and the business was terrible.
这一幅画我就卖了五百块,我对自己越来越有信心了。(Zhè yī fú huà wǒ jiù màile wǔbǎi kuài, wǒ duì zìjǐ yuè lái yuè yǒu xìnxīnle.) Only this painting, I sold for 500 yuan, and I became more and more confident in myself.
4. “就” can be used to strengthen the speech tone which is against others’ will. In this case, it’s the adverb of mood.
e.g.
别管我,我就要和他结婚。(Biéguǎn wǒ, wǒ jiù yào hé tā jiéhūn.) Leave me alone. I am going to marry him anyway.
就算没有用也没关系,我就要去中国学武术。(Jiùsuàn méiyǒu yòng yě méi guānxi, wǒ jiù yào qù Zhōngguó xué wǔshù.) It doesn’t matter if it’s useless, I’m going to China to learn martial arts anyway.
我就不喜欢喝冰咖啡,你为什么一定要逼我喝?(Wǒ jiù bù xǐhuān hē bīng kāfēi, nǐ wèishéme yīdìng yào bī wǒ hē?) I do not like to drink iced coffee, why do you have to force me to drink it?
With a premium membership, you can access all 30 questions about “就 (jiù)“, as well as online exercises for all grammar points.