What is the purpose of the words "simple,' plain, and "common"?

to appeal to as large of an audience as possible

they all mean the same thing, they explain or describe a noun.  

Explanation:

simple- means plain.

plain means simple.

definition of both:

plain= not decorated or elaborate; simple or ordinary in character.

simple= easily understood or done; presenting no difficulty.

they both meaning things that just aren't difficult to understand.

and common means=occurring, found, or done often; prevalent

basically occurringly found.

all words all have the same meaning generally, but techicnally they dont.

hope this helps :)

- "there are several movements that doris lessing was associated with. first of all, communism. she pursued her communist beliefs and included them in her writing, and was also a member of several communist book clubs. she is also strongly associated with feminism, her fight for equality and women's rights.

doris lessing is the kind of writer who has followers, not just readers. they have been engaged to her chiefly because of her involvement in major problems, such as politics and woman-ism."