SC asks how long it took me to be able to understand TV dramas. The answer is a long time. I still do not fully follow them after 9 years of living in Japan and using Japanese for over 30 years for business. Why? Because I rarely watch them, and I do not live with a Japanese family.
You learn a language by exposing yourself to a certain kind of content. The more familiar the content is, the easier it is to understand, and the easier it is to absorb the new words and phrases from that content. I needed Japanese for business, and I was soon able to understand business Japanese. I knew the Kanji so I could soon start to make out the newspaper, or parts of it. That made radio and TV news easier to understand. Baseball on TV was also understandable because I was familiar with the context. I was interested in Japanese history and tended to read that kind of material, usually containing a lot of Kanji. TV dramas represented a social context that I was not familiar with and a lot of casual colloquial language that I never came into contact with.
My son played professional hockey in Nikko for four years. Although he started basically from scratch, his casual or colloquial Japanese is probably better than mine. He picked it up from his teammates. My Japanese tends to be more neutral and formal.
The basis of The Linguist is that you learn from content that is interesting and relevant to your needs. And you expose yourself to a lot of such content through listening and reading. You do not worry about grammar rules. I certainly never did when learning Japanese or Chinese.
Instead The Linguist helps you create relationships or linkages between words to form natural phrases, and between these phrases and concepts so that you stop relying on translation from your own language. You study these words, phrases and linkages which come from the intensive listening and reading that you are doing. The key is that the content be relevant. I had no need to understand TV dramas. If I did, I would have applied myself to learning the necessary phrasing to fully follow them.