In chapter one, "Aria", of Richard Rodriguez's autobiographical book Hunger of Memory: The education of Richard Rodriguez, the author makes a series of interesting observations that explain how he, the son of two immigrant Mexican workers, began to differentiate the language he spoke at home (Spanish) with the English language.
In his own words, he explains the affect that is produced when he listens to the Mexican-accentuated Spanish spoken at home. He states how this is his own private language, to be spoken with the family only.
In contrast, he explains:
In public, my father and mother spoke a hesitant, accented, not always grammatical English. And they would have to strain—their bodies tense—to catch the sense of what was rapidly said by los gringos. At home they spoke Spanish. The language of their Mexican past sounded in counterpoint to the English of public society. The words would come quickly, with ease. Conveyed through those sounds was the pleasing, soothing, consoling reminder of being at home.
Clearly dividing Spanish as a private language and English as a public language, Richard views English as a "tool to run his mother's errands". Everything spoken in English belongs to his public life. He was to be Spanish at home only.
During those years when I was first conscious of hearing, my mother and father addressed me only in Spanish; in Spanish I learned to reply. By contrast, English (ingles), rarely heard in the house, was the language I came to associate with gringos. I learned my first words of English overhearing my parents speak to strangers. At five years of age, I knew just enough English for my mother to trust me on errands to stores one block away. No more.
Therefore, a child who is becoming exposed to English more so than his parents, will end up assimilating the target language as much as their own native tongue. The unique way in which the Rodriguez family spoke gave them their their family identity. Speaking English, will no longer be a public language for Richard and will become also a part of his social and private lives. The two worlds will merge, and Richard will no longer be a Mexican kid, but full fledged American.