3 sentences for 多年 (duō​nián — longstanding)

1. 他是我的多年老相识。

   tā shì wǒ de duō​nián lǎo​xiāng​shí.

   He is an old acquaintance of many years.

   Source: Dong Chinese Dictionary

2. 由于多年的积怨，他们谁也不理谁。

   yóu​yú duō​nián de jī​yuàn, tā​men shéi yě bù lǐ shéi.

   Due to years of accumulated resentment, they ignore each other.

   Source: Dong Chinese Dictionary

3. 这张照片是他们多年友谊的见证。

   zhè zhāng zhào​piàn shì tā​men duō​nián yǒu​yì de jiàn​zhèng.

   This photo is a testament to their many years of friendship.

   Source: Dong Chinese Dictionary