被 (bèi) — the affected-subject passive
被 bèi is Mandarin's main passive marker. The shape is the mirror image of 把: subject (the affected thing) + 被 + (agent) + verb + result. 我的手机被偷了。 = My phone got stolen. 窗户被风吹开了。 = The window got blown open by the wind. The agent (the one who did it) is OPTIONAL — drop it freely if it's unknown or unimportant: 门被打开了。 = The door got opened. Two things to know: (1) traditionally 被 carries an ADVERSITY flavor — bad things happening to you. Modern Mandarin (especially in writing and news) has loosened that, and you'll see neutral or even positive 被 sentences (他被选为班长 = he was elected class president). But in everyday speech, the negative tilt is still felt. (2) Like 把, the verb after 被 needs a result, complement, or 了 — bare verbs don't work.
The shape: subject + 被 + (agent) + verb + result
The subject of a 被 sentence is the AFFECTED party — the thing the action lands on. 我的钱包被偷了。 = My wallet got stolen. 杯子被弟弟打破了。 = The cup got broken by my little brother. 作业被狗吃了。 = The homework got eaten by the dog. Compare to active SVO: 弟弟打破了杯子 = Little brother broke the cup. Same event, different perspective. 被 puts the affected thing first and re-frames the sentence as 'something happened to it'.
The agent is optional
Unlike English, where you have to say 'by someone' or use vague 'they', Mandarin 被 lets you drop the agent entirely when it's unknown, obvious, or irrelevant: 我的手机被偷了。 = My phone got stolen (no need to say who). 门被关了。 = The door got closed. 作业还没被改。 = The homework hasn't been graded yet. If you want to name the agent, slot it right after 被: 我被老师批评了。 = I got criticized by the teacher. 他被妈妈骂了。 = He got scolded by his mom. The agent slot is for the doer, not for an instrument.
Adversity: the traditional flavor
Classical and everyday-spoken 被 leans toward bad outcomes — getting stolen from, scolded, hit, criticized, fired, fooled, rained on. 我被雨淋了。 = I got rained on. 他被老板骂了。 = He got chewed out by the boss. 那个孩子被妈妈打了。 = That kid got hit by his mom. The very fact that the affected party is the subject puts emotional weight on what happened TO them. If you're describing something neutral or positive (e.g. 'the cake was eaten by everyone' as a happy report), Mandarin often prefers 把 or active SVO instead: 大家把蛋糕吃完了 rather than 蛋糕被大家吃完了.
Modern neutral 被
In modern written Mandarin (newspapers, novels, formal speech), 被 has expanded to neutral and even good news, especially with verbs like 选 / 选为 (elect), 派 (dispatch), 任命 (appoint), 认为 (be considered), 称为 (be called). 他被选为班长。 = He was elected class president. 这本书被很多人喜欢。 = This book is liked by many. 她被认为是最好的老师。 = She is considered the best teacher. In conversational speech with everyday verbs, the adversity tint is still felt — so a beginner-safe rule of thumb: prefer 被 when something bad / unfortunate / surprising happened TO the subject, and use the active or 把 otherwise.
被 vs. 把 — flip sides of one coin
把 and 被 describe the SAME event from opposite ends. 小狗把蛋糕吃了。 = The puppy ate the cake (focus: the puppy did it). 蛋糕被小狗吃了。 = The cake got eaten by the puppy (focus: the cake's fate). The verb in both gets a result/complement (here 了). 把 requires a definite object; 被 requires an affected subject. Negation 没 sits BEFORE 被, just like before 把: 我的手机没被偷,我自己放错地方了。 = My phone wasn't stolen — I just put it in the wrong place. 不要被他骗了。 = Don't get fooled by him.
