https://www.youtube.com/watch?v=fnUc_W3xE1w
There is only one way to acquire a language.
When we understand what we are listening to or reading in this language, we CAN acquire it. 当我们能理解输入的其他语言的内容时，我们才能掌握这门语言。
With more and more comprehensive input, we can acquire a new language. 随着可理解的内容输入越来越多，才能慢慢掌握新语言。
1st stage: Listening. 第一阶段：听。
We can be very silent, and we can't even say anything or respond to a simple question. But we should know it is normal and acceptable.
在这个阶段比较沉默，无法对话很正常。
The only thing we should do is to understand what we are listening to and absorb it.
重点在于 理解 和 积累。 （这一阶段可能长达5~6个月）
2nd stage: We WANT to SAY something.
第二阶段：有了一定积累后，渴望进行输出表达。
At the very beginning, we may just say one or two words, and then a sentence, and later on more complicated sentences. This process can be fast.
刚开始是一两个单词，接着是短句，然后是复杂句。这个阶段会发展得很迅速。
大脑里的语言学习机制
Filter（理解过滤器）
- motivation-positive（动力 正相关）
- self-esteem-positive（自尊/自信 正相关）
- anxiety-negative（焦虑 负相关）
<aside> 🧠 LAD 语言习得系统
Language
Acquisition
Device
</aside>
动力越高（需要/想要学会新语言）
自信心越高（越相信自己可以学会新语言）
焦虑感越低（不怕出错）
内容理解过滤器越开放，越容易理解新语言所说的内容，也学得越快越好。
反之： 动力越低，自信心越低，焦虑越高，内容理解过率器越闭合，越难以理解新语言所说的内容，越难以学习新语言。