Opravy

I've been working out for 2 years.

During that period, I've read a lot of articles and study many programs and routines.

However, my first 1,5 years ended up in failure despite how many things I've tried.

After days of dwelling in shame, I've finally came to the conclusion: My DIET sucked and my FORMS were horrible.

Which means, no matter what kind of routine/food/excercises/... you take, everthing would be trash if you fail to create a balanced diet and practice with proper form.

On the other hand, even if you use an "inferior" routine but it goes with good diet and your forms are good, you'll definitely make some amazing gains.

So, turn back to our topic, I believe that this can also be applied to language.

I've read many methods/techniques like:Mimicking, shadowing,podcast etc...

But in my opinion, they're still unimportant and not the critical factors I should focus on.

What are the truly critical things you have to know while learning language so you can use any kind of methods (even the "inferior ones) while being sure that you won't fail even when you use every single one of them?