The other day I had to sort out some plumbing issues with a neighbour of one of our apartments (the ground floor flat had a veritable waterfall going on!), although fortunately it wasn't coming from our apartment. Or at least, I think it wasn't - I had left the keys with the neighbours, and when I picked them up later they went into detail about taps, pipes and other bits & pieces, all in french, and unfortunately their french went straight over my head, and I did that stupid thing of saying 'oui,oui, d'accord'. Duh, when you don't understand, never, never just say yes. After all this time I should have learnt my lesson by now - who knows what you're agreeing to!

Anyway, it seemed ok, although I was definitely having an 'off' day with speaking french - earlier as I had given them the keys they asked me if they should call once the plumber had been, all in french, except it went as follows;
(oh, and I'll do this in english, since I'll only get the french wrong, and you might not be able to understand it!)

les voisins: Do you mind if we called you after the plumber has been here
me: um, oui (nodding vigorously)
les v: uh? So, it's not ok to call you?
me: oh (penny dropping on the 'do you mind' part), non - pas de tout!
les v: non?
me: uh, oui, non, oui, d'accord...

eventually we got in sync, and I was able to run away...