Read the excerpt from "mother tongue." yet some of my friends tell me they understand 50 percent of what my mother says. some say they understand 80 to 90 percent. some say they understand none of it, as if she were speaking pure chinese. but to me, my mother’s english is perfectly clear, perfectly natural. it’s my mother tongue. her language, as i hear it, is vivid, direct, full of observation and imagery. that was the language that shape the way i saw things, expressed things, made sense of the world. how does tan build a central idea of her story in the excerpt?

Tan builds the idea that nonstandard forms of English are complete and valid languages.

Explanation:

The narrator of the text says that her mother, because she is Chinese, cannot speak standard English and many people ignore the way she speaks claiming that they cannot understand and that she does not even seem to be speaking English.

However, the author claims that for him his mother's English is perfect and from that he establishes the central independence of the text, where he argues that non-standard forms of English are complete and valid languages.

i can you there : )