HSK 7–9 grammar · preposition
当着
当着 — in front of, in the presence of
Pattern
+ + +
( ) can be left out · other words may come before, between and after
How it works
当着 marks someone as a witness to the action, almost always in the frame 当着…的面: "right in front of them". It implies the act is bold, awkward or deliberately public.
Examples
他当着大家的面道了歉。
Tā dāngzhe dàjiā de miàn dào le qiàn.
He apologised in front of everyone.
别当着孩子的面吵架。
Bié dāngzhe háizi de miàn chǎojià.
Don't argue in front of the children.

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