I love the tennis game,especially the  grand slam also called majors, 
I like tennis too. What exactly is a grand slam in tennis though?
They are the major tennis game with the highest reward but highly competitive. Australian Open in mid January, the French Open in May and June 
Oh so those are the most important games for players to win. Which tennis players have won the most grand slams?
On the men's single players .we have the Big four ,they are Roger Federer, Rafael Nadal, Novak Djokovic, and Andy Murray.
I know Roger Federer he has been playing forever right? 
Federer has won 20 Grand Slam singles titles, the most in history for a male player
Wow! That is a really impressive record. He is still playing too right? How old is he?