An action hit someone, and you want to give how far it drove them, not only that it hit.
序 · The move
1put the one who takes the action first, as the subjectis this the one the action lands on, not the one doing it?
2被, then the agent if you name one, then the verbagent (if any) sits between 被 and the verb, never after it?
3attach 得 directly behind the verbnothing sits between the verb and 得?
4give the resulting state the action drove them tois this a knock-on state on the subject, not a fresh action they took?
例 · Examples
1鄰居neighbours的聲音太大了，妹妹被passive marker — she takes the action吵make noise at, disturb (the verb that lands)得light link onto the resulting state睡不著can't fall asleep (how far the disturbing carried)。
The neighbours were too loud; little sister got bothered to the point she couldn't sleep.
Plain 被+V reports that the action landed (盒子被打開了 = the box got opened). 被…V得… measures how far the landing carried (妹妹被吵得睡不著 = bothered so far she couldn't sleep). One names the event, the other rates its reach.
V得+補語 rates how the subject's own action went (他跑得很快 = he ran fast — he is the runner). 被…V得… rates a state forced onto the subject by an action done to it (他被嚇得發抖 = he got scared into shaking — he is the one acted on). Same 得 link; subject does it vs. subject takes it.
結果補語 fuses one outcome straight to the verb with no 得 (吵醒 = noise-woke). 得 opens onto a fuller spilled-out state behind the verb (吵得睡不著 = disturbed to the point of not sleeping). Outcome welded on vs. state trailing behind 得.
no 得, complement welded bare: 妹妹被吵睡不著 → 妹妹被吵得睡不著
agent after the verb: 妹妹被吵鄰居得睡不著 → 妹妹被鄰居吵得睡不著
subject is the doer: 鄰居被吵得妹妹睡不著 → 妹妹被鄰居吵得睡不著 (the one who takes it is the subject)
English fuses passive and result into one clause ('was kept awake by the noise') with no separate marker after the verb; learners drop 得 and weld the state onto the verb, or front the result before the verb.