My mother tongue is German, or more exactly, Rhine Franconian dialect (dialects differ extremely in German, for example there are dialects like Low Saxon which is much closer to Dutch and English than it is to Bavarian or Swiss German).
The first foreign language I took in 5th grade (aged 10) was French, I took it from 1997-2003 and unfortunately I've forgotten most of it until now because there are so few possibilities to use it, though I was one of the best in class. And I found it very hard too, because its orthography has almost nothing to do with its pronunciation, for example there are words like "eaux" which is pronounced [o], or words like "un", "en", "in-", "an" and "on" which sound almost alike, at least to my ears...
Starting from 7th grade, I took English, which is the foreign language that I use most frequently (you won't get far without it nowadays, especially on the internet!). I finished my "Abitur" (which is a German degree allowing you to study at university) in 2006 with English being one of my three "Leistungskurse" alongside Chemistry and Maths (lit. "power subjects", which are a little harder than "Grundkurse"="basic subjects"). So I'd say that my knowledge of English is above the average of Germans of my age, but still you'll see me make a lot of grammatical and word order errors when writing in English.
My abalities are very different in that case:
Reading English is the easiest, I almost understand every English word unless very archaic or specific Latinate words are used. We had to read short stories from Edgar Allan Poe in the last year of class, and they contained a lot of such words which forced me to consult my dictionary quite frequently
When it comes to writing English, most people will understand me but like I said, I'll sometimes use the wrong word/sentence structure etc.
Speaking English is something I'm not very fluent in, it's a lot worse than writing. the reason for that is probably the radically different word order compared to German.
Understanding spoken English is probably the most difficult for me, as it doesn't happen very often that I get to speak to someone from the USA/UK etc.
Sometimes I'll meet some US army soldiers who are stationed around here (via a friend's family who have been traditionally hosting a few of them for Christmas/Fastnacht/Birthday/New Year's parties since the 50s). One of them was born in Scotland and he had such a bad accent that I had to ask 2-3x to understand what he said, while another guy from Wisconsin(?) spoke very clearly, even to his fellow Americans so I could understand him perfectly).
Then I started with Spanish in 9th grade, but I quit after less than a year because the courses were at the worst possible times and the teacher sucked big time, but anyway my French knowledge lets me understand a lot of Spanish and Italian words, but I can't really speak those languages.
Other languages I can partially understand are:
Dutch, because it's a West Germanic language just like German and English. Sure, there are some linguistic false friends but if you know the basic Dutch words like pronouns etc and know German and English, it's really easy to understand. Even the sentence structure is almost identical to German (even closer to my native dialect). I probably understand 90% of a written Dutch text,
maar ik kan het niet praten of schrijven . Spoken Dutch is something else though, I can't understand most of it, only some fragments. Fun Fact: I can understand spoken Flemish (Dutch spoken in Belgium) a whole lot better than Holland-based Dutch. I think it's because Flemish has a closer linguistic relationship to my native German dialect (on top of that, both are heavily French-influenced, I live only 150km away from the French border) than "Holland-Dutch" has.
Swedish. Though it's a North Germanic language (and therefore farther away from German than Dutch and English are) it has a lot of Low German loanwords (from the Hanse time) which make it quite easy to
första (=German "verstehen", English "understand") a good part of it. I know some basic pronouns in Swedish too, but that's all. I maybe understand 50% of the words in a Swedish text.
Another language which intrigues me is Russian. I only know some swear words though
But I can read the cyrillic alphabet without problems (as a chemistry student, you don't get around learning the Greek alphabet by heart anyway, and Cyrillic isn't a far stretch if you know both Latin and Greek alphabets). But I think that I'll
never ever be able to produce the Russian "r", it's just plain impossible! How can someone make a vibrant with the tip of the tongue? Whenever I try, the best I get out is d-d-d-d-d... though I can perfectly pronounce the German "r" which many learners consider "hard" (why that?), the English "r", the Spanish tapped "r" and even the Japanese "r"~"l" sound isn't a big problem for me, but the Russian/Italian "r" or Spanish "double r" are so impossible to pronounce :S
BTW I didn't expect these forums here to be so international, in the two days I've been here I've already seen (besides US-Americans), Canadians, Englishmen, Dutch (a lot of them actually), Italians, Mexicans, Portuguese, Swedes, Poles, Malaysians, Phillippinos etc, I didn't expect that at all
(but I seem to be the only German here, strange...)