I ask you to not worry about “why”. But worry about “when”. Students that focus on “why” have trouble gaining fluency. They ask why is this word like this, why do you say this, why why why. It doesn’t matter. People that focus on why don’t seem to improve. But students I teach that ask when can I use that word, what situation can I use that phrase, become great English speakers. Their mind is free to relax and just speak, not questioning every word, phrase or paragraph.