When someone says, 'Good on you sir!', they are giving a compliment or saying something nice to a man who has done something good or helpful. It’s like saying, 'Well done!' or 'Great job!' but in a slightly more fancy way.
This phrase is often used to show appreciation when someone makes a good choice or does something admirable. For example, if a man helps another person or achieves something great, someone might say, 'Good on you sir!' to show their approval.
So remember, it’s a way of cheering someone on and making them feel proud!