How to return a topspin down the line

my opponent always use topspin down the line i cant get to position to return it because he always make the ball far from me

Hi Mark,

It is a matter of watching the ball.  If you realise that he often hits the ball down the line try to cover that shot.  This will do two things. One it will help you to get to the ball quicker or two it will force him to hit his less favourite shot cross court.