The British Idiom – Know something by heart
Definition of Know something by heart
When you know something by heart, you have memorised it exactly and can repeated flawlessly.
Examples of Usage of Know something by heart
When I was at school we had to learn the Lord’s prayer by heart. What a complete waste of time! Apparently, Mozart could listen to a piece of music just wants and know it by heart.
Now watch my YouTube video English lesson which contains this British English idiom.