The brothers and sisters were taught how to do it by her.
2个回答

句意:她教兄弟姐妹们怎么做.

你给的原句是被动语态,by后边是动作的发出者,也就是she(主语,用名词主格),动词是teach(taught的动词原形),教谁?the brothers and sisters,教什么呢?教的是how to do it.好了,句子逻辑关系理清楚了,现在开始变:

She taught(过去式) the brothers and sister how to do it.

完成.