Foreign language learners wonder when they'll be able to read and listen to that language and understand everything. But even native speakers don't comprehend everything they read or hear. What percent of words do we need to understand in order to comprehend a written or oral passage?
What happens when an English proofreader in Korea, who rails against people for not consulting native speakers to assist with proofreading, doesn't follow his own advice? He gets a wake-up call!