Not exactly my mistake, but I thought I would share. I eat regularly at a local Indian restaurant and really like spiced tea. They had a rather young and inexperienced waiter who made me my favourite spiced tea but didn't know he had to put tea in the pot. I got spiced water. After a conversation resembling "The Emperor's New Clothes" fairy tale, we had a good laugh and I got my spiced tea. His English has improved a lot and I've learned the relevant phrases as well.