What are the top 10 hardest words to say? The 10 hardest English words to pronounce, according to Reddit Worcestershire. Pronunciation: Wuss-ter-sheer. This one is hotly debated. Choir. Pronunciation: Kw-eye-er. Isthmus. Pronunciation: Is-muss. Sixth. Pronunciation: Siks. Penguin. Pronunciation: Pen-gwen. Otorhinolaryngologist. Read more…