How will I know? How do you know? Songs and movies all ask the question which implies a simple answer. Betty Everett and Cher said, “It’s in his kiss.” According to Whitney Houston, you’ll feel shy and week (need to resist conducting critical analysis of those lyrics right now).
I’m less concerned about the asking the question that begins a relationship; instead, I’m focusing on the end.
“How do you know when something is finished?”