[Maurice]

I've learned two languages more or less fluently as an adult (Spanish and Portuguese). In both cases my method was the 'long-haired dictionary' Seriously, I learned both on the ground through immersion, which is obviously the best way.

I also made some progress on French (I don't count it as one of my languages, but I can get by when I need to - traveling in north africa for instance). THis I started through classes at the Alliance Francaise here in NY. Later I spent some time in Paris, took classes and also had a private tutor - and got much more out of the latter.

I think constant practice (and constant correction) is necessary - if you can afford a private tutor instead of a class, I think you'd get much more out of it.