– Manuscript – Welcome to English in a Minute! A stone has a very hard surface. To set something into one would not be easy. So what do you think "set in stone" means? Speaker A: Dan, what are you doing this weekend?Speaker B: I might go hiking with a friend. But I'm not totally sure yet.Speaker A: Well, if those plans aren't set in stone, my friend Kristen wants you … [Read more...] about Set in Stone (Idioms)