Answer:
I come in different colors and shapes. Some parts of me are curvy some are straight. You can put me anywhere you like but there is only one right place for me.
I can be long or short. I can be grown or bought. I can be painted or left bare. My tip can be round or square. (one word)
I start new then become old. Start clean but be one dirty. I usually start big then become little.
The more you take of me the more you leave behind.
I am pinched by grandmas
The answer I give is yes, but what I mean is no. What was the question?