Secondspawn: Mummy, what’s your favourite word?
Me: Hmmm. Interesting question. I shall have to think about it. And of course my favourite word probably changes all the time
– pause –
Me: I think it’s “incommensurability” at the moment.
Ss: I know what that means.
Me: You do? what does it mean?
Ss: It means that you can’t hold something in a certain way.
Me: I think you may be right.
frizzyLogic 
just lovely – and what is his favourite word?
Heavens – has Joseph been reading Goethe?
It was the other one actually… he’s only just mastered English. But somebody he knows is very well up on the German philosophers.