<human>: Can you condense the text into three sentences or less?

If I spoke only English, nothing else. I had an argument about this a while ago, and the opposing side said that you can learn languages just by being exposed to it and that your brain makes connections and learns the language (said this with an example: a man holding out a bag of salt, talking. Your brain makes a connection that the man is talking about the bag of salt and therefore you understand every single word he is saying if you are exposed to this repeatedly). I can't imagine this possibly happening. You learn languages by using another language you are already fluent in as a tool (for example, I know what a Korean word means because I know what it is in English).
<bot>: Can you learn a language, post infancy, by being exposed to it daily? Without using things such as translations, etc.