Well, if yours is a silly question, I'm afraid mine might be a silly answer...but I believe a lot of people actually do just break the yarn rather than cutting it...but for myself, I don't seem very good at it,and so I cut it. Also, if it's something that needs weaving in with a yarn needle, I find it much easier to thread the needle if I've cut, rather than broken the yarn.
Now someone correct me if I've missed a point somewhere along the line!
Seems simple, right? I have yet to be able to "break" any yarn. Hands, teeth, and might have all been called into action to no avail. I honestly wish I could break yarn rather than always having to dig out scissors every time.
I've found most acrylic yarns break pretty easily. Usually I cut the yarn as opposed to "breaking" the yarn; I personally don't like the frizziness when you break the yarn.
Also, Clover has a yarn cutter pendant that I just LOVE! When I lost my first one, I went to store after store until I found another...lol...What's awesome about the pendant is well, it's a pendant...lol...Just find something sturdy to thread through the top of the pendant and wear it around your neck!
--The member formerly known as Demonica
"You must be the change you wish to see in the world."
- Mahatma Gandhi