This is a very interesting TED talk by an English teacher in Dubai, who warns against losing other languages in favour of one global language. One of her arguments is that there is knowledge contained within each laguage and if we lose the less commonly used languages, we also lose that knowledge. In my experience as a Spanish learner I have found that there words that cannot be translated into another word, but a whole sentence is needed to describe the concept. This has been an interesting insight into learning taht there are concepts that are more easily concieved in other languages. Feel free to share your thoughts below. I would be happy to discuss this with you!