Just some thoughts on learning a foreign language through another learned language.
If English is your L1, many people only attempt to learn another language through English. And that’s fair enough, but it might not be the most practical if you have other tools at your disposal. Professor Arguelles strongly suggests people that dream of being a polyglot learn French and German. With English, French and German at your disposal there is a wealth of material available for the language learner. The same could also be true for Japanese and Chinese, and to a lesser extent, Korean.
But this is the argument for using a L2 because of materials access and availability. How about using your L2 to learn L3… or L3 to learn L4 even? Sometimes it is just more practical and efficient. If you’re an English speaker that has studied Spanish to a high level for instance, would it make more sense to learn Portuguese or Italian through English, or to learn them through Spanish? My vote would be Spanish because of all of those similarities in grammar and vocabulary. My own personal example is for using Korean as tool for studying Japanese, again, due to grammatical similarities and the large cross-over in vocabulary due to the Chinese influence. It’s not just a matter of making it easier for yourself though, there are other things to consider.
Like what things? Well, in using your L2 to learn L3 you’re going to appreciate the finer details of your L2. You will effectively be learning your L2 in more depth by studying your L3. These are things I have found with my own studies. Through elementary level Japanese study I consolidated and clarified things in Korean I already knew but didn’t really know. You may learn things you never knew, you may have a few a-ha moments when you finally understand something that you have been using but didn’t really know the why behind it, or you may just find it more time-efficient because of the similarities. There are of course negatives that include misunderstandings of explanation and what-not, but you do always have the dictionary option to cross-check anything you’re not certain of.
But basically, what I’m mainly talking about is using a language that is similar to one you are learning to lessen the burden. It doesn’t have to stop there though. Professor Arguelles’ suggestion of learning French or German first is a valid one. Even if these languages aren’t similar to the one you are studying, due to the quality of materials available they may still be the best option. I know a number of people that have learned English and now use it learn other languages simply because materials aren’t available in their L1. Personally, I love Assimil, so at least a written understanding of French is a must because it opens so many doors for me in the future.