是...的
Reach for this when the action is already done and you want to ask or tell when/where/how/who it was done. 'When did you arrive?' '是昨天到的.' The fact that you arrived isn't news; the listener already knows it. You're zooming in on a detail of an established past event. This is one of the most useful patterns in spoken Chinese — natives use it constantly.
Structure
[SUBJECT] 是 [TIME/PLACE/MANNER] [VERB] 的
shì... de
How to Think About It
是...的 is a spotlight, not a tense. It puts a frame around whatever sits between 是 and 的 and says 'THIS part is the new information.' The verb itself is already shared knowledge. Compare '我昨天来的' (focus: yesterday) vs '我坐火车来的' (focus: by train). Swap the middle and you've changed what the sentence is actually about, even though the bare facts are identical.
Examples
我是去年来中国的。
Wǒ shì qùnián lái Zhōngguó de.
I came to China last year. (focus: last year)
他是坐飞机来的。
Tā shì zuò fēijī lái de.
He came by plane. (focus: by plane)
这本书是在北京买的。
Zhè běn shū shì zài Běijīng mǎi de.
This book was bought in Beijing. (focus: in Beijing)
Common Mistake
Learners use 了 when they should use 是...的. 了 announces 'this happened.' 是...的 assumes it happened and zooms in on a detail. If the listener already knows the event occurred and you're answering when/where/how, 了 is wrong.
我昨天来了北京。
我是昨天来北京的。
Don't Confuse With
了 (perfective)
Use 了 to ANNOUNCE that an action happened ('I went to Beijing'). Use 是...的 when the action is already established and you're specifying when/where/how it happened.
的 (possessive/modifier)
The 的 in 是...的 is part of the structure, not a possessive marker. '我的书' (my book) is a totally different 的. Pattern-的 always comes at the end of the sentence.
是 + Noun + 的 (attributive)
'这是红色的' = 'this is the red one' is an attributive use, describing a noun. The 是...的 emphasis pattern always wraps an ACTION (a verb), not an adjective alone.
Practice
我 ___ 昨天晚上到的。
Show answer
是
他是在上海工作 ___。
Show answer
的
Put in order: [是 / 的 / 来 / 我 / 一个人]
Show answer
我是一个人来的。
Translate to Chinese: 'I learned Chinese in college.' (focus on where)
Show answer
我是在大学学中文的。
Answer this question using 是...的: 你是怎么来的? (How did you come?)
Show answer
Example answer: 我是坐地铁来的。 (I came by subway.)
Hear It in Real Episodes
This pattern appears in 20 Fluentide episodes: