If you have a snapped key, it is possible to fix it. However, depending on the severity of the break, it may be necessary to replace the entire key. If the break is small and only the tip of the key has broken off, you may be able to reattach it with superglue or another adhesive. If the break is more severe, you can try to file down the jagged edges so that they fit together more snugly, but this may not be very effective. Ultimately, if your key is severely snapped, it is best to replace it.