Re: Idioms are tough...
A French friend of mine in UK is married to a Doctor. She ordered a fridge-freezer and when they delivered it just fitted, with mm to spare, in the alcove in the kitchen 'the delivery man said, perfect, just what the doctor'd ordered'. She was amazed ad asked ' how do you know my husband is a doctor?'
Not an idiom, but I couldn't understand why there were so many 'French models' in Soho. Then a parent complained about the homework set for their son 'bring French letter' was written in his homework diary! Mind you, the French call them 'capotes anglaises'!
Another French friend was caught out by this badly. She had post natal depression (2 babies in quick succession in the UK, no family support) and she decided to put an add to teach some French for a bit of pocket money. She put an ad in the local paper and nobody warned her- sadly it tipped her over the edge. Ad read : Private French lessons in your home or mine + tel number. Not funny that one, as she ended up in psychiatric hospital having ECT.
My absolute favourtie British sign is 'heavy plant crossing - I always swore I would do it one April 1st, dress up as a daisy and bounce in front of cars, but never dared.