If only Definition 1 of 3Pro Tip 1/3Regret Expression Shows a sense of regret over past actions or events. If only I had accepted that offer. Pro Tip 2/3Unchangeable Past Indicates an event that has already happened and cannot be changed. If only I had arrived on time. Pro Tip 3/3Imaginary Scenarios Often used to imagine different outcomes in a past situation. If only I’d been there to help.