于

（表示时间、处所、范围等）:

• 闻名于世界

  famous all over the world; of world renown;

• 长江发源于青海。

  The Changjiang River rises in Qinghai Province.

• 他生于1950年3月9日。

  He was born on March 9, 1950.

• 运动正处于高潮。

  The movement is at its high tide.

（表示动作的方向）:

• 求助于人

  call to one's aid; ask people for help;

• 问道于盲

  ask the way from a blind person; seek advice from one who can offer none

(用在动词后面，表示交与， 付出等）:

• 嫁祸于人

  shift the misfortune onto sb. else; put the blame on sb. else;

• 经过大家的努力， 困难的局面终于让位于顺利的局面。

  As a result of collective effort, the difficult situation changed into a favourable one.

（引进对象或事物的关系者）:

• 不满足于已经取得的成绩

  not rest content with one's achievements; not rest on one's laurels;

• 献身于教育事业

  dedicate oneself to education;

• 忠于祖国

  be loyal to one's country;

• 新鲜空气有利于健康。

  Fresh air is conducive to health.

• 这样于你自己不利。

  It won't do you any good.

（表示起点或出发点）:

• 出于无知

  out of ignorance;

• 出于自愿

  of one's own free will; of one's own accord;

• 认识来源于实践。

  Knowledge originates in practice.

（表示比较）:

• 今年小麦产量高于往年。

  This year's yield of wheat is higher than ever before.

• 人固有一死， 或重于泰山， 或轻于鸿毛。

  Though death befalls all men alike, it may be weightier than Mount Tai or lighter than a feather.

（表示被动）:

• 见笑于人

  be laughed at;

• 见知于世

  be recognized by society

（姓氏） a surname:

• 于谦

  Yu Qian