The polish lady I work with has a reasonably good grasp of English but does not understand idioms. Obviously now she has told me this I am trying to communicate using as many as possible.

What are your favourites?

http://www.idiomsite.com/

“Thick as two short planks” has always been a good one. Translates into German as “Dumm wie stroh” – ‘stupid as straw’.

Next time she asks your opinion, tell her it’s not up to you, it’s down to her.

[pedant mode] Most of the “idioms” on the idiomsite seem to be straight metaphors or even just aphorisms/truisms. The essence of a true idiom is that the listener/reader can’t possibly work out the intended meaning from the actual words, e.g “hard cheese” to mean bad luck [/pedant mode]

‘Well I’ll go t’foot of our stairs’

Meaning ‘How surprising!’ in Lancastrian.

‘Well I’ll go t’foot of our stairs’

A perfect example of an idiom – utterly impossible to work out the intended meaning by examining the actual words

[pedant mode] this actually should read “well I’ll go t’t’foot…”, because the full expression requires “to the” and therefore two apostrophes of omission are needed [/pedant mode]