I speak Finnish as my 1st language so I'm writing another language at the moment too.
We started to learn English around the 2nd-3th grade (aka when we were 8-9 years old) in comprehensive school but I neglected that pretty effectively and could say I learned it properly after I started to discuss here. But that's just written, I guess my spoken English is still pretty horrible (pronouncing etc). Even of course I got my basics from the school.
Since we are bilingual country (Finnish - Swedish) , we have this law which I think is a bit stupid. It means that also the 2nd national language is a compulsory part of curriculum in every school. Swedish started in the 7th grade (around 12-13 years old) and I included it as a part of my upper secondary matriculation examination like I included English too. I haven't still written or spoken Swedish after my matriculation examination (2008 ) at all and now when I started it in open college again I noticed I've forgotten lot.
I also know some very basics of Spanish. I think it'd be an interesting language to learn also more. It's a bit pity that I managed to take only one course of it during the upper secondary school (I was 18 then).