QUOTE(TSax @ May 31 2006, 01:41 PM)

Think of it like learning another language.
If you can speak, read and write English fluently then would you expect to have to start from basics to learn another language? (if you're an amazing linguist, bear with me for this analogy).
The fact that you can hold a pen, form letters and write words will help, to an extent, with the writing.
The fact that you know the phonetic sounds of letters will help with reading (if it's a Western language).
A good grasp of grammar will help with your learning.
BUT....
You'll still have to start from scratch with the vocabulary, although some words may well be recognizable.
The grammar is likely to be different..
and even when you've got the grammar and vocab under your belt there's still the accent to master, plus all the little nuances that make you sound like a natural speaker, rather than an English person trying to speak the language.
That's not dissimilar to the process of learning jazz if you've got a classical background.
I reckon I've got to the point where my vocab is enough to get by, but a bit limited to express myself as I really want to. I've mastered some of the grammar and can usually make myself understood (although I do still come up with the odd howler), and having come this far I can see just how far there is to go to become a native speaker. Fabulous learning process though.
I very much like the anology but by that reckoning I need to go back to school and need to look at my reading and writing all over again!!
I am a 'Senior Citizen' born again Clarinettist (haven't touched once since I was 17 and now loving it.) I have been a lifelong Jazz fan and my ultimate aim is to be able to play and improvise, meanwhile I'm doing the ABRSM grades (Classical lessons) Grade 3 and studying a Blues/Jazz course at home, that I found on the net.