就是 (jiù shì) for emphasis/definition
就是 stamps an equals sign on the sentence — 'is precisely', 'is exactly', 'that is to say'. Use it to define a term, point to the very thing under discussion, or close down ambiguity. It's softer than English 'precisely' and shows up everywhere in spoken Chinese, from explaining vocabulary to confirming someone's guess.
Structure
[A] 就是 [B]
[A] jiù shì [B]
How to Think About It
Think of 就 as 'exactly that, no other' and 是 as 'is'. Together, 就是 means 'is exactly this and only this'. It doesn't just connect A and B — it eliminates other possibilities. When someone asks 你是张老师吗?, replying 我就是 is more emphatic than 是的: 'I am precisely (the one you're looking for).'
Examples
这就是我们今天要讲的核心话题。
Zhè jiù shì wǒmen jīntiān yào jiǎng de héxīn huàtí.
This is exactly the core topic we're discussing today.
修电的人就是电工。
Xiū diàn de rén jiù shì diàngōng.
People who fix electrical work — they're called electricians.
他就是我跟你说过的那个新同事。
Tā jiù shì wǒ gēn nǐ shuōguo de nà ge xīn tóngshì.
He's the new colleague I told you about.
Common Mistake
Learners use plain 是 where 就是 is needed for emphasis, or sprinkle 就是 in front of any 是 to sound fluent. 就是 has actual semantic weight — it asserts identity or pinpoints. In a neutral statement like 我是学生 ('I'm a student'), adding 就是 sounds odd unless you're contrasting with another claim.
你好，我就是中国人，很高兴认识你。
你好，我是中国人，很高兴认识你。
Don't Confuse With
是……的
是……的 highlights the circumstances of a past event (when/where/how it happened). 就是 identifies or equates. 我是昨天来的 (I came yesterday) vs 这就是答案 (this is the answer).
也就是说
An extension of 就是 used to rephrase or restate — 'in other words'. Use it at the start of a clause that paraphrases the previous one.
Verb + 就是了
Same characters, different mood. Tacked onto the end of a verb, 就是了 means 'just do it, end of story'. 你试试就是了 = 'just try it'. Don't confuse it with the equational 就是.
Practice
Fill in the blank: 这___是我要找的人。 (This is exactly the person I'm looking for.)
Show answer
就
Fill in the blank: 中国的首都就___北京。 (China's capital is Beijing.)
Show answer
是
Arrange: 我 / 在找 / 就是 / 这本书 / 的 (This is exactly the book I was looking for.)
Show answer
这本书就是我在找的。
Translate to Chinese: This restaurant is exactly the one I told you about.
Show answer
这家餐厅就是我跟你说过的那家。
Use 就是 to define or identify something for someone who's confused.
Show answer
你说的“包子”，就是一种用面皮包着肉或菜的中国早餐。
Hear It in Real Episodes
This pattern appears in 1 Fluentide episode:
Related Grammar Patterns
Acquire by listening
Hear 就是 (jiù shì) for emphasis/definition in real Chinese, not in a textbook.
Fluentide picks the next news episode at your level, so this pattern shows up again and again in real context. The transcript marks it, the audio drills it. Free to start, no card.