* The origins of English: The English language itself has roots going back centuries to Old English (circa 450-1150 AD), which evolved from Germanic languages.
* Colonization and the arrival of English in America: English arrived in North America with the first English colonists in the early 17th century. So, you could say the earliest form of English spoken in the US is around 400 years old.
* Evolution of American English: From the moment English arrived, it began to evolve and diverge from British English, developing unique features like vocabulary, pronunciation, and grammar. This process continues to this day.
* Linguistic diversity: It's also important to remember that the English spoken in the US today isn't homogenous. It's influenced by various dialects and accents, reflecting the diverse origins and histories of the American people.
Therefore, while we can pinpoint the arrival of English in North America, it's difficult to define a single "age" for the English spoken in the US, as it has been constantly evolving and diversifying for centuries.