knee high to a grasshopper

【口】(指人)很年幼时；小时后。

knee to knee (with)

(与...)促膝。

bow [bend] the knee to sb

(非正式用法)屈从；崇拜(某人)。

bring sb to his knees

破坏；毁灭(某事或某人)；(尤指)使完全屈从。

give a knee to

给予援手。

go [fall (down)] on one's knees

下跪求饶或祈祷。

gone at the knees

(非正式用法)(指裤子)膝部因久穿而破裂、磨损致不成形。

learn sth at one's mother's knee

小时后学的；自母亲处学到某事。

on bended knee(s)

恭敬地；跪着。

on one's knees

谦逊的；卑屈的；缩减力量。

on the knees of the god(s) (=in the lap of the god(s)

听天由命。

Sb's knees knock (together)

【口】感觉很害怕；露出害怕的样子。