안녕하세요!
Proper pronunciation can make as much difference as the comma contrasting meanings: “Let’s eat, Grandma” and “Let’s eat Grandma”. While pronouncing things the wrong way sometimes can change the meaning of a sentence, it can also just make me sound more like a beginner and less like the fluent person I’m pretending to be.
You also don’t know that you’re doing or saying something wrong until someone tells you – this is the peril of self-taught language learning.