形容詞 sincere:

1. open and genuine; not deceitful
2. characterized by a firm and humorless belief in the validity of your opinions
   同義詞：earnest, solemn

1. How can I persuade you that I am sincere?
   怎樣才能使你相信我是真心實意的呢?
2. I think he is sincere and quite without affectation.
   我認為他為人誠摯，毫不做作。
3. Sincere congratulations on your son wedding please convey our best wish.
   令郎喜結良緣謹此致以誠摯的祝賀并請轉達最美好的祝愿。
4. Please accept my sincere thanks and best wishes.
   請接受我誠摯的感謝和最美好的祝愿。
5. Please accept our sincere apologies for the error in your bank statement.
   為你的銀行報表中的錯誤，請接受我們誠摯的道歉。
6. Please give my sincere regards to all the members of your family.
   請向你全家轉達我真摯的問候。