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蛋糕 被 弟弟 吃完 了
Words in this sentence
蛋糕
cake
被
quilt; to cover (with); (literary) to suffer (a misfortune); used to indicate passive voice (placed before the doer of the action like "by" in English passive-voice sentences, or, if the doer is not mentioned, before the verb); (since c. 2009) (sarcastic or jocular) used to indicate that the following word should be regarded as being in air quotes (as in 被旅游[bei4 lu : 3 you2] to "go on a trip")
弟弟
younger brother
吃完
to finish eating
了
(completed action marker); (modal particle indicating change of state, situation now); (modal particle intensifying preceding clause)
Particle