What I want to hold on from today's class

First, language is used as form to achieve power. There are standards set by those who are in power, and those who follow or master the standards are likely to be successful. There is a perceived importance to have standards in a language, so that there is a concise power in communication.
Second, there is a culture of power which are not the same as having authority. Authority is something given or entrusted by others, while power can be defeated or terminated if the person does not have authority.