Principle: Use the language in order to learn it
The single most important principle is this: you acquire your language when you use it in context. Primarily this means reading and listening a lot.
It takes a lot of time with the language to become ﬂuent, and most of that time should be spent with natural input that is both comprehensible and interesting to you.
That can mean reading texts, listening to podcasts, watching videos, writing stories, ﬁnding natives to speak with, or anything else that takes your fancy. In addition, speaking and writing are great ways of solidifying your knowledge and getting feedback.
You will see this principle repeated throughout your language learning journey.
This principle holds because learning a language is a skill you must practice and reﬁne. In many ways, it is more like learning to ride a bike or play an instrument than learning facts or rules.
It is the reason traditional methods of learning—memorising lists of words and grammar rules—is so ineﬀective.
This kind of study will let you learn about a language, but it is a poor way to acquire it.
You do not need to be able to complete grammar exercises to use a language correctly for the same reason you do not need to understand gyroscopic forces to ride a bike.
We must realize that learning does not turn into acquisition.
While the idea that we first learn a grammar rule and then use it so much that it becomes internalized is common and may seem obvious to many, it is not supported by theory nor by the observation of second language acquirers, who often correctly use “rules” they have never been taught and don’t even remember accurately the rules they have learned.