The British and Foreign languages

[Marcellus]

So, I was wondering, what do people think is the most useful second language to learn in Europe and why?

English

But for native English speakers (i.e. the British), I would say any of French, German, Spanish and Italian, because these are the languages of the places Britons seem most likely to visit. They are also quite 'international' languages, so are useful in that respect too.