If you master grammar but can't pronounce anything, or your vocabulary is too small, or you have no confidence to speak, or you don't learn the way natives say

If you master grammar but can't pronounce anything, or your vocabulary is too small, or you have no confidence to speak, or you don't learn the way natives say things through trial and error, then all your efforts are completely wasted. Language isn't just some word for word translations and a new sentence structure, it's much much deeper than that. The only thing that is required to learn a language is tens of thousands of hours of practice.