5 sentences

1. 他诚恳地向我道歉。

   tā chéng​kěn de xiàng wǒ dào​qiàn.

   He apologized to me sincerely.

   Source: Dong Chinese Dictionary

2. 他的道歉态度非常诚恳。

   tā de dào​qiàn tài​du fēi​cháng chéng​kěn.

   His apology was very sincere.

   Source: Dong Chinese Dictionary

3. 他因迟到向大家诚恳致歉。

   tā yīn chí​dào xiàng dà​jiā chéng​kěn zhì​qiàn.

   He sincerely apologized to everyone for being late.

   Source: Dong Chinese Dictionary

4. 不论是谁说的，我为那句话诚恳道歉。

   bù​lùn shì shéi shuō de, wǒ wèi nà jù huà chéng​kěn dào​qiàn.

   I sincerely apologize for that remark, whoever made it.

   Source: OpenSubtitles

5. 他的诚恳解释驱散了大家心中的疑虑。

   tā de chéng​kěn jiě​shì qū​sàn le dà​jiā xīn zhōng de yí​lǜ.

   His sincere explanation dispelled everyone's doubts.

   Source: Dong Chinese Dictionary