Every type of negligence claim must show four basic elements: duty, breach, causation, and damages. A plaintiff has to demonstrate that the defendant owed him or her a duty of care, the defendant breached the duty, and that breach caused the plaintiff to suffer damages. 

Unlike a criminal trial, a plaintiff does not need to show proof beyond a reasonable doubt. Instead, the plaintiff must prove that what he or she alleges is more likely than not to be true. Attorneys sometimes refer to this burden of proof as a preponderance of the evidence. A plaintiff in a personal injury case must establish each of the four elements of negligence by a preponderance of the evidence in order to prevail at trial. 

Duty

In general, everyone owes one another a duty of reasonable care. Drivers have a duty to one another to drive with care. Doctors have a duty to treat patients with care. 

Breach

Plaintiffs must be able to explain how an act or omission breached a duty of care. For example, plaintiffs could show that a defendant failed to follow traffic laws or a doctor failed to diagnose a condition. 

Causation

Plaintiffs must show that a breach of care caused direct or indirect injury. Causation is arguably the most important element of a negligence claim and often the most difficult to prove. 

Damages

Injury is typically the easiest element to prove. A plaintiff may use evidence such as medical records or photographs to show injury, A plaintiff can show the economic damages from an injury with evidence such as medical bills or pay stubs reflecting lost wages.