But that said, I can cut off quarter hours here and there, and I thought I'd write a few things about language learning that I have learned.
1. Becoming fluent as an adult takes longer than you think. Really. Estimate how long it will take you (unless you are one of those rare pick-it-up people) and multiply by two.
2. Backsliding erases gains in some areas. I am amazed today when I look at the feats of literature I attempted in Polish five years or more ago. Letters, short stories, translations of unusually popular essays or columns I wrote in English. Now banging out a request for comment to a Polish contact is a brain-crunching chore. But that said, my letters may have been rubbish, and my short stories and essays were usually corrected by a tutor before I wrote out the final draft. Also, I was underemployed then, so I had the time to laboriously tell Polish Pretend Son the parish news and write about Edith Stein po polsku.
3. Reading. Writing. Listening. Speaking. They are four different languages on their own. Being able to read easily in Polish is most definitely not the same as being able to write fluently in Polish. And for me it is easier to speak Italian than to listen to it--which sounds like a moral failing, but is merely how my brain currently works.
In a way, this is good news. If you're a graduate student in theology, and the task before you is to master enough German to read theological texts, you don't have to go to the trouble of learning to write, listen to, or speak German. You can just learn the grammar and the (limited) diction in a cold-blooded way. You don't need to go to Germany. You can study the grammar with a tutor (explaining that you're not interested in speaking right now--maybe later) and write down all the words you think you are going to know and memorise them on cue cards. Then you start reading short German theological texts, writing down the words you don't know, and memorising them, too.
However, if you want to read, write, listen and speak fluently in German, you will have to dedicate four times as much time. If you are a woman or man of leisure--and you really want to become bilingual quickly--I recommend an hour of reading, an hour of writing, an hour of listening, and an hour of conversation every day. After your gruelling four hour session, have a nap. Maybe have this nap in the middle.
4. Brains are lazy and do not want to study a foreign language for four hours a day. They don't see the point, especially if you don't need these languages to survive. Therefore, you have to train them. You have to remind them over and over that wówczas means "then" and invece means "instead." Brains like repetition. My brain likes Mulieris Dignitatem because St. JP2 keeps using the same words over and over.
5. The temptations to quit will be enormous. Your foreign friend will laugh because you used the wrong verb. Your tutor will laugh at your favourite foreign language band. Your classmates will burst into giggles at your terrible pronunciation. Most of your tutors will be beautifully fluent in English while in your target language you sound to yourself like a six-year-old. You will go back to a children's book you mastered over two years ago and understand only half. Welcome to my world of pain.
6. The gains involve astonishing jumps. It's like losing weight. One day the scale suddenly says you have lost 5 pounds after being stuck on the same sad number for weeks. One day the wax falls out of your ears and you understand that your tutor took his daughter to the beach. One day your tongue gets up and tells Catholic Poland via television that the Synod involved a cynical attempt to change the doctrine of the priesthood. It's an overnight success---after years of hard slog (and bouts of the inevitable goofing off).
7. Watch out for rivals. This is a weird and sad one. There are people who, for whatever nefarious reasons of their own, will deliberately undermine your confidence in your linguistic abilities. Admiring the talents of your fellow learner, you may have asked them for advice or shown them a piece of writing you need perfected. You do this confidently, thinking everyone is as nice as your tutor, and this person tells you that you are completely incomprehensible and your work irredeemable. Well, some people torture cats, too. They slap babies. So don't quit.
8. "You have to live there," said French-and-German-speaking Nulli, who is wondering why he is learning Japanese. Our sisters speak Spanish fluently because they lived "there" while teaching ESL--and they keep it up through Spanish-speaking social activities. I very reluctantly believe that, yes, to reach the heights of fluency, e.g. to pass the European Union C2 exam, does depend on a long stay in a country where everyone around you speaks your target language. But that said, you can get very far at home.
9. A tutor with highly quirky English who is obsessed by the beauties of his own language is a treasure to be cherished. You can speak to such people in their own home countries--where they don't speak English every day--by Skype. The joy of speaking to someone who struggles to speak English as you struggle to speak his language is immense. You don't mind his mistakes, so you don't mind your mistakes, either.
10. It's a never-ending journey, but I think it's worth it.