These irregular varieties must be memorized. But don’t fret—with observe, they’ll come to be next nature. humorous - People usually leave out the second "o," improperly believing that just the "u" is required rather than the "ou" diphthong. Think of it similar to this: The "r" is so weak here, https://troytajpw.blogscribble.com/28170754/helping-the-others-realize-the-advantages-of-spelling-mistakes-by-dsl