He has turned over a new leaf

A classic idiom!

"He has turned over a new leaf" is a common English expression that means someone has changed their behavior or attitude for the better. It is often used to describe a person who has made a conscious effort to improve themselves or their ways, and is now moving in a more positive direction.

The phrase is thought to have originated from the idea of turning over a new page in a book, or starting a new chapter in one's life. Just as a new page is blank and waiting to be filled with new content, a person who has "turned over a new leaf" is starting fresh and leaving their old ways behind.

Here are a few examples of how you might use this phrase in a sentence:

• After his recent mistakes, John has turned over a new leaf and is now working hard to make amends.
• Sarah used to be a heavy smoker, but she's turned over a new leaf and has been a non-smoker for years.
• The company has turned over a new leaf and is now focusing on sustainability and environmental responsibility.

Overall, "he has turned over a new leaf" is a phrase that suggests positive change and growth, and is often used to express admiration and encouragement for someone who has made a conscious effort to improve themselves.