system
A chat on subreddit /r/me_irl
human
A big part of learning English is knowing where to put the emphasis in the word.

 I was listening to someone speaking and she said: man-DAT-ory instead of MAN-datory. 

And thats when it became clear how to spot non native speakers who speak english really well.  She could speak mandarin (she was chinese) but her English was as fluent as mine with very little accent. But some words just really strike you if they're pronounced with a different emphasis even if they're technically pronounced right.
gpt
I can't pronounce 50% of English words right and i read soooo many books but almost noone where i live speaks English.. my cousin came and we were talking about books and I pronounced Scythe like Sky-th and he corrected me, it's Sith apparently