Answer:
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)
What breaks when you say its name?
How many letters are there in the English alphabet?
What can fill a room but takes up no space?
I am an insect and the first part of my name is the name of another insect. What am I?
Whoever made me don't want me. Whoever bought me don't need me. Whoever use me don't know me.