Never. Writing tutors will help you become independent, resourceful writers. By editing or “fixing” your English you will not learn how to become a better writer, rather you will just become dependent on having someone else do your work for you. You can expect your instructor to discuss organization and give you strategies for structuring your paper. They will also help you with grammar, word choice, cohesion, paraphrasing, and citations. In certain cases, your tutor might model several different ways you might rephrase an idea.