To those who are reluctant to comment because they're worried about making lots of mistakes - don't worry, just do it. This isn't a language class, nobody is grading you on your grammatical mistakes. Hell, some of us native English speakers can get pretty careless as well (always somewhat sheepish at the fact that a lot of the non-native English speakers tend to be more polished than I am). As far as more involved diaries go, one idea might be to offer translation services. I'm perfectly happy to translate anything from Polish, French or German. And I'm far from the only one here with language skills.
If we do try multilingual stuff it might be worth trying to figure out which languages make sense - presumably only the major ones (Spanish, French, German, Italian). How many lurkers are there who are native speakers in those languages but don't feel comfortable commenting in English? How many people can read those languages?
The previous chart is from the full report, while the following one is from the summary [PDF]: When the capital development of a country becomes a by-product of the activities of a casino, the job is likely to be ill-done. — John M. Keynes
Yes, you can list multiple languages as you mother tongue. 94 % of the Irish list English as their mother tongue, while 11 % list Irish...
Did any of you know that 9% of the population of Luxembourg have Portuguese as their mother tongue? Or that the Luxembourgers are the only country where they think that learning French is more important than learning English?
Also, for the "more Italian than French mother tongue", I'd say maybe the more numerous immigrants in France than in Italy may not have French as mother tongue... Auferre, trucidare, rapere, falsis nominibus imperium; atque, ubi solitudinem faciunt, pacem appellant.
But another explanation is simply that the conclusion is false. It's 13% vs. 12%, and the margin of error is around 2%...
By the way, another reason not to take the figures on Italian vs. French too seriously is that the study does not include Switzerland...
The survey was run on 15+ population. Their numbers for that group are 49m in Italy, 44m in France, 8.6 m in Belgium.