Short answer=yesOriginally Posted by a_hyperbole
If you have a basic musical aptitude (an "ear"), you can learn to play the instrument you were born with.
I'm curious. What makes you believe you can't sing? If you can't match pitch, you need to train you ear. If you can't read music, that can be learned, as well.
Voice lessons are mainly about learning to play the instrument you have. Breathing, posture, tone, diction, expression, and musical interpretation all figure into it. You develop an awareness of what your body is doing while singing. And you learn a certain adeptness and confidence that only comes from singing in public.
To be honest, not everyone is gifted with a naturally beatiful voice. But I've found it pretty amazing what some people have done with what voice they've had.