While I understand what the article is getting at, the best way that I have found to learn is to be submersed in it. Make it so that you have to learn. Ideally you want to learn it as a kid but if you are an adult trying to learn a second language, you have to first have a need I think or be really motivated. It can be difficult to learn a language and really, what they teach in school is not what you really need. I’ve learned more from the natives here in Mexico than I did in school and I started at 8 years old!