[shmat]

Stephen Krashen's Input Hypothesis says that you need comprehensible input. Immersion as a complete beginner does not give you much comprehensible input. He advocates that you need what you listen to be 95% understandable, which means you have to start with very, very basic input. Personally, I find 50 - 60% is good enough for me to improve if only slowly. I went to France this year after 7 months of listening to French for 2 hours a day. During that 7 months I went from DELF A1 level material (complete beginner) to YouTube videos from native speakers talking about things that interest me (such as physics). I took a French immersion course in France and was tested at the beginning as B1 level. So, the input hypothesis method got me from complete beginner to intermediate in 7 months without immersion. I did not do any speaking until after 5 months of listening.

[andai]

That's interesting. I learned of it second hand, and must have got the wrong idea. I thought the whole point was that it's the way everyone learns their first language, as babies? When you start, nothing is comprehensible. But with enough input, everything becomes comprehensible!