I guess having twice the vocabulary (or 2x, 3x...) gives you more tools to think.
Sometimes, when I'm trying to figure out something hard, I think/write in english (not my native language), and the thoughts seem to develop more logically (can't explain why though). So I guess it's not just learning, but using it.
Yes. But experiencing the emotional part of a foreign language is also important, especially when you want to read their novels, watch their movies, experience their cultures, etc.
English is my second language and I was unable to understand the underlying emotional part of an expression. Imagine what Independence Day movie will look like without those inspirational speech. I'm getting better now. But still, there always lots of space to improve.
Ultimately, they concluded, as more countries and people across the world start to participate in a global economy and, consequentially, begin to learn foreign languages, more rational and favorable (read: risky) decisions will be made.
Sometimes, when I'm trying to figure out something hard, I think/write in english (not my native language), and the thoughts seem to develop more logically (can't explain why though). So I guess it's not just learning, but using it.