I still trip over them all the time, Murray, but the one that has caused me the most trouble over all, I'm sure, is pants / trousers. For those who don't have the trouble: Pants, in America, are the divided clothes on wears on the bottom half - underpants, panties, or underwear are the more intimate garments you'd rather your boss didn't see. Trousers are... archaic and formal. In Britain, trousers are outer wear, pants or all types are not to be shared on the streets.

Cookie and biscuit are also a problem, but don't earn the surprised looks. Also school/college vs. University.

Simplest things cause the most trouble.

-J