于
Pinyin: yú
at; in
Example sentence
他生于一九九零年。
Tā shēng yú yī jiǔ jiǔ líng nián.
He was born in 1990.
What 于 means
于 (yú) is an Chinese word meaning “at; in”. It belongs to the Grammar Words topic and appears at HSK 4, so it is one of the words worth learning early when you study Chinese.