My mum is the same, I usually just say hmmmm or occassionaly say have you is it good? She rarely has a definitive answer and sort of waffles, says she can't remember or just ignores it. There's not really much else can do. Very occassionaly now, but I used to do it more at first as I thought it meant mum wasn't enjoying program, I'd ask if she wanted to watch something else instead but she'd always say no, or I'm watching this, or something similar so I rarely bother now unless she keeps going on about it Mum will tell me that she's seen program before and then ask what just happened, or who someone is and I do think to myself, funny you've seen it before but don't know what happens or who one of main character is, but I don't say that to mum.