英语短语 "fall on one's knees" 是一个生动的动作表达，核心含义是“跪下；屈膝”，但更强调主动或因强烈情绪/目的而做出的“下跪”动作，常隐含“求饶、祈祷、屈服、极度恳求”等引申义。
字面指“膝盖着地”的动作；引申为通过下跪传达虔诚、绝望、服从或恳求的情感。
该短语通常作谓语，后面可接介词短语、不定式或从句，补充说明“下跪的对象/目的”。
因犯错、绝望或急需帮助而下跪，请求原谅或救助。
He fell on his knees and begged the judge for mercy.（他跪下向法官求饶。）
When she realized she had lost her child, she fell on her knees and pleaded with passersby to help.（当她发现孩子丢了，她跪下恳求路人帮忙。）
在宗教或心灵寄托的场景中，下跪表达敬畏或祈求。
She fell on her knees in the church and prayed for her sick mother.（她在教堂里跪下，为生病的母亲祈祷。）
The villagers fell on their knees and thanked the gods for the rain.（村民们跪下感谢神灵带来雨水。）
因权威、压力或无力反抗而下跪，承认对方的优势。
The defeated general fell on his knees before the victorious king.（战败的将军在获胜的国王面前下跪。）
They would never fall on their knees to a tyrant.（他们绝不会向暴君屈服下跪。）
因悲伤、震惊等强烈情绪而失控下跪。
Upon hearing the news of her husband’s death, she fell on her knees and burst into tears.（听到丈夫去世的消息，她跪下来失声痛哭。）
物主代词搭配："one's"需替换为具体的形容词性物主代词（his/her/their/your等），如"fall on his knees"（他跪下）、"fall on their knees"（他们跪下）。
时态变化：原形是"fall on one's knees"，过去式是"fell on one's knees"，过去分词是"fallen on one's knees"（如：He has fallen on his knees many times for forgiveness. 他多次下跪请求原谅。）
与类似短语的区别：
"get on one's knees"：更强调“主动蹲下/跪下”的动作，可用于日常场景（如系鞋带）；
"fall on one's knees"：更侧重情绪驱动或被动性（如因绝望、虔诚而下跪），语气更强烈。
"fall on one's knees" 是一个情感色彩浓厚的短语，核心是“下跪”，但通过上下文可传递“恳求、虔诚、屈服”等深层含义，常用于文学、口语或情感强烈的场景中。