[ekjhgkejhgk]

I speak 4 languages, each learned in a completely different way.

We can argue what "best" means, but from my experience the fastest is buy a grammar with exercises, read the grammar and do the exercises.

> Get a native speaker (...)

It's extremely hard work for the other person until you're past a certain level. I tried this, and they struggled even though I could already speak a bit, they they were a professional and I was paying them well. If you're at zero, this is fantasy.