There are a few factors that come into play when determining if someone should be held liable for the harm they caused another through their negligence. The first factor is whether or not the person had a duty to act in a certain way to prevent harm. For example, all drivers have a duty to operate their vehicles in a safe manner so as not to cause accidents. If a driver breaches that duty and causes an accident, they will likely be held liable for any resulting injuries.
The second factor is whether or not the person had knowledge that their actions could reasonably lead to harm. This is where things can get tricky, because it can be difficult to prove what somebody knew or should have known at the time of an incident. However, if it can be shown that the person was aware of the risks involved in their actions and still chose to proceed anyway, then they will likely be found negligent and held liable for any resulting harm.
The third factor is causation, which basically means that the negligent party's actions must have actually caused the victim's injuries. This may seem like a no-brainer, but it's important to remember that there could always be other factors at play (e.g., pre-existing medical conditions). So even if somebody breached their duty of care and acted negligently, they will only be held liable if those actions were actually what led to the victim's injuries.