I know there are plenty of esoteric programming languages that are designed to be incredibly difficult to work with, like Malbolge, Brainfuck, and PikaLang, though programs written in them can still be compiled and run by a computer.
There are lots of constructed linguistic languages, like Esperanto and Toki Pona, but for most of those they are designed to be easier to learn or have other functional benefits. Are there any linguistic languages where the goal is to be difficult to speak, write, and understand, while still being actual languages?


Are you describing English without saying it?
Which reminds me, the spelling vs. pronunciation would have to be inspired by English. You can’t find anything in the dictionary unless you know the etymological origin of the word. If you don’t know that, your guess of the first letter is guaranteed to be wrong, and you’ll end up opening the book at a completely wrong section. When you hear a new word, it’s easier to just ignore it and get on with your life.
Ha, I had this conversation with my Grade 4 teacher. She would always say “check the dictionary” (when I’d ask how to spell a word I’d only heard) and I would complain that it wasn’t easy to figure out how some words started. Mnemonics, pneumonia, as examples.
I had such a hard time finding /ɪˈpɪt ə mi/. I tried so many different spellings that I ran out of ideas.
However, mnemonics and pneumonia are just diabolical. There’s zero chance that you’ll ever find those… which reminds me, this new language would have to be very big on silent letters. Basically like French, but cranked up to eleven, because anyone foolish enough to study this language deserves to suffer.
As there are vastly more vowel sounds than there are vowel letters, you might as well use only consonant letters to write all the vowels. This language is just one big middle finger to all the other languages out there.