In 2024, about 74.1 million or 23% of people age 5 and older in the US spoke a language other than English at home. Spanish accounted for more than half. American Community Survey (ACS) data identifies 11 non-English languages that are the primary language in the homes of more than a million people.

Using imaging of brain activity, neuroscientists have found compelling evidence for a neural network dedicated to language in the adult human brain.

During a reading lesson, Mateo, an elementary multilingual learner (MLL) in a Delaware public school, read “sit” as “seat.” Jon Kittle, his reading interventionist, walked him through the short vowel sound, but Mateo made the same “mistake” and grew frustrated. Kittle began to wonder if these “errors” were actually the result of Mateo applying what he knew from Spanish, where the letter “i” carries the sound of the English long “ē.”

Even after being entirely forgotten, the tonal languages we hear during our first months of life permanently alter the physical wiring of our brains, according to new imaging research on international adoptees.