What does 'shadows' mean?

[Keith Clarke]

On 13 Oct 2011, at 12:46, Francis Nugent Dixon wrote:

> To define the workings of a four-stroke engine, I would always
> prefer English.
> To tell a woman how much I love her, I would always prefer French !
I once tried to explain the the (non)workings of a four-stroke engine to the woman I love - the language I used was... rather rapidly out of her earshot! ;-)
Best,
Keith..