HSK 2 grammar · pattern
是…的
是…的 — emphasizing details
Pattern
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Detail: the time, place or manner that is stressed
( ) can be left out · other words may come before, between and after
How it works
是…的 wraps a detail of a completed event — when, where, or how it happened — to put the emphasis on that detail rather than the event itself.
Examples
他是昨天来的。
Tā shì zuótiān lái de.
It was yesterday that he came.
我是坐火车去的。
Wǒ shì zuò huǒchē qù de.
I went by train.
Related

See it in a story
In the app, 是…的 is underlined wherever it appears in the stories you read, and practised with sentences from them. Free.