Writing about web page http://www.bbc.co.uk/languages/yoursay/lost_for_words.shtml
Have you seen the section of the BBC language website “Lost for words” with people’s language blunders? Just seen that one I sent in has been posted:Film Trailers
Helpfully there’s an editors note:
I was wanting to find out whether there was a trailer for the film I was going to see, and as I didn’t know what the German word for trailer was, I decided to make it up: Vorspiel. I reasoned that it would mean something like “before the performance”. However, it was clear from the surprised/amused look on the ticket seller’s face that I’d got it wrong. It turns out I asked whether there’d be any foreplay… oops! Trouble is, I still don’t know what I should have said – I just know I won’t be asking that again!
Editor’s note: You were on the right path. The German word for trailer is Vorschau.