把...当成...
Reach for this when you want to say someone treats, considers, or regards X as Y — and you want to highlight the act of categorizing itself. It's a specialized 把 construction where the verb is fixed as 当成 ('treat/regard as'). Use it for relationships ('treat me as family'), priorities ('treat exercise as a task'), and mistaken framings ('treated her as a stranger'). Conversational register; the slightly more formal version swaps 当成 for 当作 or 视为.
Structure
Subject + 把 + [A] + 当成 + [B]
bǎ... dāngchéng...
How to Think About It
Plain 把 fronts the object so the verb can act on it; 当成 is the verb that does the acting, and the action is 'classify as.' You're moving A into the mental box labeled B. The 成 means 'into' — A becomes B in the speaker's framing. If you drop 成 and just say 当, you can still be understood, but 当成 is what learners should default to.
Examples
他把我当成了他的好朋友。
Tā bǎ wǒ dāngchéng le tā de hǎo péngyou.
He treats me like one of his best friends.
别把这件事当成小问题。
Bié bǎ zhè jiàn shì dāngchéng xiǎo wèntí.
Don't treat this as a small problem.
她把每天的散步当成一种休息。
Tā bǎ měitiān de sànbù dāngchéng yī zhǒng xiūxí.
She treats her daily walk as a form of rest.
Common Mistake
Learners forget that 把 requires a specific, definite object. Generic 'people' or 'things' without context sounds off — the listener needs to know which A is being reclassified.
他把女孩当成赚钱的工具。
他把那个女孩当成了赚钱的工具。
Don't Confuse With
把 + Object + Verb + Result
Generic 把 disposal — the verb and result vary. 把...当成... is the specific case where the action is 'treat as.'
认为...是...
Pure opinion ('I think A is B'). 把...当成... emphasizes the treating/handling behavior, not just the belief.
看作...
More formal/written. Use 把...当成... in speech, 看作 in essays.
Practice
Fill in: 别____这件事当成笑话。
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把
Fill in: 他把锻炼当____任务，反而觉得有压力。
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成
Arrange: 把 / 朋友 / 他 / 当成 / 我 / 了
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他把我当成了朋友。
Translate to Chinese: Don't treat work as your whole life.
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别把工作当成你的全部生活。
Write a sentence using 把...当成... about how someone treats another person or thing.
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她把这只猫当成了家里的孩子。
Hear It in Real Episodes
This pattern appears in 2 Fluentide episodes: