I have booked one ways for years because every time I checked the cost was the same and I had more flexibility. Now airlines are back to charging a lot less for a RT than two one ways.

I never see anywhere what happens when you want to cancel or change the second leg of your trip. Once you have already traveled the first leg. Can you do that same as if you haven't left?

This is a general airline question but I can't find a category for that.