Even though I'm a native speaker, I've made quite a few mistakes (only these two come to my mind now):
· I always thought "tela adhesiva" was "tela de siva" (never asked what "siva" was though)
· And only until I was an adult I realized "H. Ayuntamiento" had a dot after the H, so I had always thought the word was "Hayuntamiento" instead of "Honorable Ayuntamiento).
