How does Oluo define a microaggression and what is one example of a microaggression?

Oluo states that within the world of social justice, microaggressions are defined as “small daily insults and indignities perpetrated against marginalized or oppressed people because of their affiliation with that marginalized or oppressed group” (130). She goes on to provide examples, such as telling someone of color that they are skilled at speaking English.