1. One wrong thought may cause a lifelong regret. 

2. I only regret that I have but one life to give for my country. 

3. We regret to learn from your letter that...

3. Sentencedict.com is a sentence dictionary, on which you can find good sentences for a large number of words.

4. The regret penetrated to his marrow.

5. I didn't regret the choice I had made.

6. We regret to inform you that...

7. We regret that we are unable to .....

8. Failure is never quite so frightening as regret.

9. I deeply regret what I said.

10. She will regret and she will want you here.

11. I regret not studying harder.

12. I heard of his death with profound/deep/great regret.

13. He felt a kind of happiness mingled with regret.

14. Do not waste time with regret.

15. I regret spending so much money on a car.

16. Never regret something that once made you smile.

17. The decision could be one he lives to regret.

18. I regret doing that.

19. Do as I tell you,or you'll regret it later on.

20. I regret to say that we can't stay here any longer.

21. I regret my actions.

22. I regret to see you again become a starting point discrete.

23. Never regret anything because at one time it was exactly what you wanted.

24. Some regret only one person listen, I'm very sorry, I still cherish, everything.

25. Youth is a blunder; manhood a struggle, old age a regret. 

26. What we acquire without sweat we give away without regret. 

27. He who will not learn when he is young will regret it when he is old. 

28. Don't go off at half cock and accept any offer you'll regret later.

29. Remember to look back upon your mistakes from time to time, but never regret them.

30. like a fertile ground for learning, as long as hard work, there will be many of the fruit; if lazy work, when other people jump when the harvest dance, you have a regret.