- Learn Japanese as it exists in its natural environment
- Almost no previous experience necessary
- Can pick up slang words
- Meet truly interesting people from interesting places
- Learn anywhere, any time
- Some pen friends may object to your spouse*
- May pick up words mismatched to your gender
- Can pick up slang words
I've maintained a long time that getting a pen friend -or now we're in the digital age, an email friend- is among the best ways of learning a language. My personal plan for learning Chinese was basically: buy a book and audio CD that teaches the basics, then find mail-friends online.
To be honest, I never ended up learning Chinese all that long, but then Japanese has to take precedence in my life. Maybe when I've settled into Japan, I'll start up the Chinese again. I digress, but still, if you're interested, I feel I got on pretty well as a beginner with just those two resources: the beginner's book, and mail-friends**.
The great thing about email friends is that they cost you nothing (unless you end up marrying one of them... Whoops!), and even if they don't teach you, you're still learning.
In fact, as much as I want to like people for trying to teach me, its those email friends that correct me every sentence that I end up emailing the least often. I've taken a very 適当 (casual) approach that probably has more to do with passively absorbing what sounds right than actually putting in effort and being proper.
In any case, if you want to learn how to speak proper Japanese, you're going to want to read books, not chat to random people... If you can't read books yet, then its probably too early to worry about speaking properly, unless you want to do business in Japan, or ask your girlfriend's dad if its OK it to marry his daughter (shoot there's another thing I forgot to do!)...
But even so, email friends are helpful at pretty much any level of ability.
The only thing I would say against email friends is that I get a hell of a lot higher uptake from girls. I don't mind this (though my wife might), but it does mean that I'm not absorbing whatever language usage is more common amongst my own gender. The other thing, which I feel is related, is that many of these email friends will stop emailing as soon as I tell them I have a wife.
This lead me more recently to just omit that fact until asked... Certainly it means you can get a bit more practice in before it comes up, but in actuality I suspect its better to make it one of the first things to say so that you can find the email friends that are actually looking for friendship and save yourself some bother at the same time.
To close, I think its also worth pointing out that its never been a better time for gathering some email friends, with mobile internet as its current price, and email-capable mobiles, you can easily afford to do this anywhere. Free Japanese support, wherever you want, whenever you want, from native speakers of the language.
* if you're lucky, your spouse won't object to your pen friends ;)
by the way, I'm interested in hearing if anyone else seems to find they lose a lot of email friends on account of having a spouse, because it seems very strange to me... Please comment!
** on second thoughts, I should add online dictionaries to the list of necessities, but online dictionaries are far easier to find than good pen friends or good books.