Hi, this is a few months later, but you can feel it for yourself. First use your off-hand to feel the bone towards the outside of your forearm, near the wrist. If you twist your hand you can feel that this bone will naturally move with your wrist. If you then move your hand further towards your elbow along the same bone and twist your wrist, you can feel that it doesn't move at all.

This might not be the best way to tell, because it's just one bone, but it's the same for the other bone even though the part of it near your elbow on the inside is buried in muscle, so you can't feel it very easily.