The best way I know to learn Spanish fast is to start with Interlingua. It worked really well for me. First, you can learn Interlingua in a short time. Castellina discovered that people learned it so well in six days that they could write texts in Interlingua. The average might be closer to 15 days for English speakers, but that’s still very fast. And my own experience bears it out, because I was practically fluent in a couple of weeks.

After you learn Interlingua, you can learn many other languages quickly. This has been documented most thoroughly with languages like Spanish, Portuguese, Italian, and French – any Romance language – which you can learn about twice as fast as usual. When I learned Interlingua, my Spanish seemed to pour into my head! It works with other languages as well.

So you save a lot of time and effort in the long run. Basically, you’re giving yourself the advantage that jcd mentioned. You’re whisking through your second language and moving right on to your third, related language. Interlingua also helps you to understand your own language better – why words mean what they do, and so on.