I think the issue is similar with bilingual people. Since I started speaking English, my thoughts regularly switch from one language to another, especially when I can't remember the word I want in that language. It's also a great exercise during the learning process.
But what caught my attention in the article was the link between language and self-awareness. I think it makes sense: the more complex ideas you can convey to other people, the more complex ideas you can convey to yourself too.
Maybe that's what make us different from the other animals?