To Give the Go Ahead

To give someone the go ahead means to give permission to do something. Another expression that's very similar is to green light something, or to give something the green light so it can be used as a verb or a noun. To lose your train of thought: You were thinking about something but now you cannot remember what you were thinking about. If you lost your train, you wanted to go somewhere, but you can't go. But if you're going home by train? No, no, no. I've lost my train of thought. You've missed your train. You've arrived too late. We both lost our train ofthought. That's our expression. And we could also say