胜败乃兵家常事(Shèngbài nǎi bīngjiā chángshì)Soldiers are used to victory and defeat.

Explanation

当别人或自己失败的时候，我们一般用这句话来安慰、劝说。意思是：胜利和失败都是正常的，没有什么可伤心难过的。
This sentence is usually used to comfort people who have failed at something, meaning there is no reason to be sad or frustrated.
Words:

采纳cǎinà:be approved;
赢yínɡ:win.

Sentences

1、Jiǎ:Zěnmebàn, gōngsī yòu méiyǒu cǎinà wǒde fāng’àn.
甲：怎么办，公司又没有采纳我的方案。
A: What should I do? Again, my plan was not approved by the company!

Yǐ: Shèngbài nǎi bīngjiāgchángshì, bùyào zháojí,mànmànlái.
乙：胜败乃兵家常事，不要着急，慢慢来。
B: Soldiers are used to victory and defeat. Don’t worry, and just take it easy.

2、Jiǎ: Zuótiān MànLián shūgěi DéGuóduìle ,zhěn kěxī'a!
甲：昨天曼联输给德国队了，真可惜啊！
A: Yesterday, Manchester United lost to a German team. What a pity.

Yǐ: Shèngbài nǎi bīngjiā chángshì,bùyào shāngxīn le,MànLián huìyíng de!
乙：胜败乃兵家常事，不要伤心了，曼联会赢的！
B: Soldiers are used to victory and defeat. Don’t be worried, they will win again.