3 sentences

1. 他为人谦虚，从不矜伐自己的功劳。

   tā wéi​rén qiān​xū, cóng bù jīn fá zì​jǐ de gōng​láo.

   He is a humble person who never boasts about his own achievements.

   Source: Dong Chinese Dictionary

2. 他在演讲中刻意弱化了自己的个人功劳。

   tā zài yǎn​jiǎng zhōng kè​yì ruò​huà le zì​jǐ de gè​rén gōng​láo.

   He deliberately downplayed his personal contributions in the speech.

   Source: Dong Chinese Dictionary

3. 他在这次科学研究中立下了不小的功劳。

   tā zài zhè cì kē​xué yán​jiū zhōng lì​xià le bù xiǎo de gōng​láo.

   He made a significant contribution to this scientific research.

   Source: Dong Chinese Dictionary