"How's the revision going?"
"I'm on a break."
It isn't helped by the fact that no parent (unless he or she is a teacher) can possibly understand how GCSEs, AS levels and A2s work these days. You get bits sat early, modules, coursework and written exams, and they all account for different percentages of the final mark.
This is why, when you go on and on about the one part of a GCSE that you actually remember from being 16 yourself, your teenager will say wearily, "But that's only 15% of part 3 next year", and you realise you know nothing, absolutely nothing.
Some parents bribe their teenagers to work hard. I've heard of all sorts of sweeteners, from cash to holidays in Ibiza.
Others pay by results – three good A levels and I'll buy you driving lessons.
In our house, we haven't got that kind of money, so we limp through in an atmosphere of absurd enthusiasm.
"I'm not going out at all until after my AS exams," said my 17-year-old the other day.
"That's such a good idea!" I said. "It's only a few weeks! Then you can go out all you like!"
On Sunday evening, I found her in the hall pulling on her shoes.
"I thought you weren't going out until after the exams," I said uncertainly.
She looked at me with pity. "It's a house party," she said.
Like I said, I know nothing. Absolutely nothing.