South Slavic languages have 1-1 mappings thanks to an engineer in disguise [1]
https://en.wikipedia.org/wiki/Vuk_Karad%C5%BEi%C4%87#Linguis...
https://en.wikipedia.org/wiki/Vuk_Karad%C5%BEi%C4%87#Linguis...
Spanish is also very predictable. While there are a few exceptions (like 'c' can be 'c' or 's'), they are very easy rules to follow, so never any surprises.
English and French are in the batshit crazy category. It's pretty much all random, you just have to know from memorization.
English is hard to both read and write.