Hello.
I had an idea to make English, but each phoneme is swapped for an opposite. This is easy to do for vowels - for example, /i/ and /u/ are opposites, because one is front and the other is back. I tried to figure out a similar system for consonants and have been stuck ever since. So, how would you calculate an opposite for /m/, or /h/, or /r/? I’m sure there must be a way to do it, but for the life of me I can’t figure it out.
There’s also central vowels, as well as close/mid/open (plus several degrees in between) vowels, so it’s not that straightforward for vowels either.