Human: What's the difference between a sprained ankle and a broken ankle? Assistant: 
A sprained ankle is an injury to the ligaments in the ankle. It can be caused by a sudden twist or fall, which causes the ligaments to stretch beyond their normal range of motion. A broken ankle is more severe, as it involves the bones in the ankle breaking. This type of injury usually occurs from a direct blow to the bone, such as a fall from a height or a car accident.