Of course I'll simplify the language I use when talking to people who have limited English skills, like kids or others learning the language.

Sesquipedalian means use of very long words, not quite the same as using a rich vocabulary.

> incorrectly

I sometimes pronounce words incorrectly that I'm very familiar with. What happened was I read the word a lot, yet had never heard it spoken. My mind would make up a pronunciation as I read, and eventually thought that was the real pronunciation.