Second, I picked randomly one lesson from the last link (“Greetings”) to listen, and to my surprise, instead of Portuguese I came across with long explanations in English mixed with parts of Portuguese. I don’t see how you can create LingQs, if another languages are used.
Is it because is premium content and therefore things are different?
The first lesson is now available for free, so you are welcome to take a look and see how things work.
The primary audio file is free on their website, as you say. However, the premium lessons include a PDF file for each lesson and an optional extra audio file, both of which are paid-only resources.
Restrictions for premium content are different. Our goal is to find various types of premium content and integrate it into the LingQ system. Lessons in a single language are easier to implement, but we recognize that many users are interested in additional explanations and in the idea of being taught a language through their own.