How to learn a language fast?

Going through a 15-hr video course might not be the best way to learn a language.

More than anything, it leaves you prone to forgetting since you did not put what you learn into action.

Here is what works for me.

(1) Read the official docs and use what you are learning to build something.

For example, when I was learning Golang, I used what I learned to build a "quotes" CLI. A CLI that shows a random quote every time you run it.

Stupid idea, I know, but it helped me learn basic Go in a few hours. Plus, it was fun.

You can do the same.

When learning a language, build a small project in things it is good at.

When learning ReasonML, build a simple web app.

When learning Rust, build a simple CLI.

(2) Read the code of popular projects.

To find the best practices of a language, it is best to see popular projects in that language. You will get answers to questions like - Which package manager to use? What should be the code structure? What language features to use and what to ignore? etc.

Use GitHub Advanced Search to find those projects (filter by language, sort by stars).

(3) Finally, use those best practices.

Using those best practices, either make a side project or contribute to an open-source project. You want to cement that learning into your memory

These three steps will get you from 0 to an intermediate level in comparatively less time.