Demonstrate means to do then the other person do after.
Sentence- my teacher will demonstrate the math lesson.
If you want your characters to have king and queen like speaking style, then you can use plural verb instead of single. For example, a dialogue can be: "We like this crockery." Also, try to include old words and old speaking styles. For example, instead of "I want this book", write "We wish this book to be a part of our collection." You can research the medieval English words. Do not use too difficult ones of them, that are difficult to identify today, just use the words that sound old and that don't need a dictionary.
canoniz'd bones", "hearsed in death", and "ponderous and marble jaws"
I'll tell you. M' father, Pip, he were given to drink, and when he were overtook with drink, he hammered away at my mother, most unmerciful. It were a'most the only hammering he did, indeed, 'xcepting at myself. And he hammered at me with a wigour only to be equalled by the wigour with which he didn't hammer at his anwil. - You're a-listening and understanding, Pip?"
In this excerpt, the action of "hammering"
hope this helps