When writing a restrictive clause, introduce it with the word "that" and no comma. However, if the subject is or was a human being, use "who" to introduce the clause. When talking about people in defining (restrictive) relative clauses, who is preferred to that.
Maya and Cassill are both American writers. They were born at such a time when America was going through a major change regarding justice and inequality among people of different races. These prolific writers heavily wrote about this in their books i.e stories, novels, poetry etc.
<em>Maya Angelou was born on April 4, 1928, while Ronald Verlin Cassill was born on May 17, 1919. </em>
Both these eminent personalities have won many awards. <u>Maya is known for her non-fictional work while Ronald was famous for his modern fiction stories.</u>
