Question
the  ends of my plant are brown, why and how do i  prevent it?

Answer
I assume this is an indoor plant.  Many indoor plants suffer from this problem.  Most of the time it is an evnvironmental issue such as humidity that causes this problem.  Over watering can also cause the problem.  My suggestion is to cut off the dead ends and begin to spritz the plant each day with fresh water.  Use a slow release fertilizer such as osmocote 14-14-14 designed for houseplants.  I hope this helps to prevent the browning leaves.  Good Luck.