I made a mistake.
He made a mistake.
I admit my mistake.
I acknowledge my mistake.
Anybody can make a mistake.
I must have made a mistake.
I made a bad mistake on the test.
I am afraid he will make a mistake.
She accused me of making a mistake.
I made a serious mistake on the test.
I'm sorry I opened your mail by mistake.
I'm afraid I took your umbrella by mistake.
Do you think he made that mistake on purpose?
Excuse me for opening your letter by mistake.
If you find a mistake, please leave a comment.
Someone must have taken my umbrella by mistake.