Rule 701 Opinion Testimony by Lay Witnesses

When a regular person (not an expert) testifies in court, they can share their opinion only if it comes from something they personally saw, heard, or experienced. They cannot speculate or guess about things they did not directly observe.

The opinion also has to actually help the court understand something important. For example, a neighbor could say "the driver looked drunk" based on what they watched, but they could not offer an opinion about something outside their personal experience.