No one is perfect, and we all make mistakes. It can be kind of cliché to say that, but the vital point is that we have to admit it, without making that statement an excuse for ourselves. Maybe you miss some of your work unfinished before or accidentally infuriate your partner, and so you need to learn how should we face our own mistakes. Let’s learn the English expressions in admitting our mistakes and fault in this passage!
I was the one to blame.
I never intended it that way.
I’m totally responsible for this matter.
I admit what I’ve done is wrong.
Sorry, I know this was my fault.
I’m so sorry. I dropped the ball.
I messed up really bad.
It’s my fault. Please forgive me.
After admitting your own flaw and fully apologize for that, you can also add ‘How can I make it up to you’, or think of a feasible way to resolve the problem, and even more, to promise ‘it won’t happen again’, so that this quarrel can end peacefully.