Most Common Mistakes in English – An English Learner’s Guide Did you know that the plural of "sheep" is "sheep" (not "sheeps")? Some mistakes in English are incredibly common, even among advanced learners: irregular plurals, using "have done" instead of "did", incorrect prepositions ("arrive to" instead of "arrive at"), placing commas where they shouldn't be and omitting them when they are necessary... This book will teach you how to avoid some of the most common grammar and vocabulary mistakes English learners make. Patron Membership Required You must be a Patron member to access this content.Already a member? Log in here