For people whose mother languages usually have a one-to-one letter to sound correspondence, knowing in advance how to pronounce these words is challenging
That's my biggest mistake in oral English.
This week, I had to look up how to pronounce "Midas" in English (Midas is related to the Insurance industry in the UK). I thought it was "MY-das" and it turned out to be "MI-das", for once!
Bearing in mind the important efforts from our governments to actually make people ignorant by making public education a real shit, it's no surprise not even native speakers have the tools to know how to pronounce words in their own language