1
on one's knees
表示跪着的状态或求饶。
He was on his knees looking for the ring.
他跪在地上寻找戒指。
膝盖；膝
先理解核心含义，再看它在真实句子里的用法。
膝盖；膝
the joint between the thigh and the lower leg
He was on his knees looking for the ring.
他跪在地上寻找戒指。
人体中大腿与小腿之间的关节或关节区域,位于腿部中部。
In humans, the joint or the region of the joint in the middle part of the leg between the thigh and the shank.
人体腿部的铰链关节,连接胫骨和腓骨与股骨,前面由髌骨保护
hinge joint in the human leg connecting the tibia and fibula with the femur and protected in front by the patella
马及类似动物的腕关节,相当于人类的手腕。
In the horse and allied animals, the carpal joint, corresponding to the wrist in humans.
四足动物中股骨与胫骨之间的关节；相当于人类的膝盖
joint between the femur and tibia in a quadruped; corresponds to the human knee
She fell and scraped her knee on the pavement.
她摔倒了，在人行道上擦伤了膝盖。
The doctor asked me to bend my knee slowly during the examination.
医生让我在检查时慢慢弯曲膝盖。
His knees hurt after he ran the marathon.
他跑完马拉松后，膝盖很疼。
表示跪着的状态或求饶。
He was on his knees looking for the ring.
他跪在地上寻找戒指。
比喻用法，意为使某人或某组织屈服或濒临崩溃。
The crisis brought the company to its knees.
这场危机使公司陷入困境。
描述突然跪下的动作。
She fell to her knees and begged for forgiveness.
她跪下请求原谅。
Not this
I have a pain on my knee.
Use this
I have a pain in my knee.
英语中表示身体部位内部的疼痛时，通常用介词in，而不是on。膝盖是关节内部疼痛，所以用in。
Not this
He got down on his knees to propose.
Use this
He got down on one knee to propose.
英语中，单膝跪地（on one knee）表示求婚，双膝跪地（on both knees/on his knees）表示乞求或尊敬。注意膝盖数量的区别。
Focus on the distinctions below. Other candidates are kept compact until a reliable usage note is available.
弯曲膝盖
You should bend your knees when lifting heavy objects.
举重物时应弯曲膝盖。
跪下
He got down on his knees to pray.
他跪下祈祷。
膝盖受伤
The athlete suffered a knee injury during the game.
那名运动员在比赛中膝盖受伤。
膝盖疼痛
Many older people experience knee pain.
许多老年人经历膝盖疼痛。
膝盖无力
She felt weak knees after the long hike.
长途徒步后她感觉膝盖无力。
跪着
He was on his knees, scrubbing the floor.
他跪着擦地板。
使某人屈服
The economic crisis brought the country to its knees.
经济危机使这个国家屈服了。
跪着；处于绝望境地
He was on his knees begging for forgiveness.
他跪着请求原谅。
两腿发软（因紧张、激动等）
Seeing her again made me go weak at the knees.
再次见到她让我两腿发软。
膝盖骨连着大腿骨
In anatomy class, we learned that the knee bone connects to the thigh bone.
在解剖课上，我们学到了膝盖骨连着大腿骨。
膝盖深的水中，在海滩某处
We waded knee deep into the cool river.
我们涉入齐膝深的凉爽河水中。
发长 /iː/ 音 (如 see, free)
Use knee naturally, then get feedback on meaning, tone, grammar, and phrasing.
Revisit a common error or keep this word in your review list.
音似'你'，联想'你的膝盖'。
[object Object]
All listed words share the /i/ vowel sound with 'knee' (spelled 'ee' in some, 'e' in others). Be careful: 'knee' begins with a silent 'k', unlike the pattern words which have pronounced initial consonants.
Dictionary facts from ECDICT, WIKTIONARY.