Everyone can sing. Everyone can also sing better than they do at their present level. No matter what the starting point, everyone has the capacity to improve. There is a common misconception that you can either sing or you can't. But the voice can easily be approached as the instrument it is, and you can train your voice as you would any other instrument. Just as you wouldn't begin piano lessons and then expect to play Beethoven's Moonlight Sonata tomorrow, you will have much more fun learning how to sing if you're both patient with yourself and willing to work hard.