In the city where I grew up, you can still hear Polish on the radio and walk into Italian groceries where the oldest customers still speak nothing but Italian, cultural artifacts of waves of immigration that took place over 100 years ago.

Assimilation works on a generational pattern. Recent immigrants will cling to their native language, even as they must learn to speak a little English just to function. Their native language is part of their home that they carry with them. It's a rare immigrant who doesn't feel pulled two ways much of the time. Also, it's comfortable to stay with groups of people whose social ways you already share. It feels safer. Often, it is safer.

Some older immigrants will never learn English, but will remain cloistered inside the immigrant community until they die. Some of these folks aren't even so old, but they have no facility for language and remain isolated by their lack of linguistic talent. The community will not abandon these members, but will continue to facilitate their lives by speaking the native language in their presence.

The second generation, and some of the youngest of the first generation, are the ones who pick up English. They will be bilingual, often in the uncomfortable position of translating for their parents and grandparents even concerning medical problems. They will assimilate as part of their growth into young adulthood, as a way of differentiating themselves from their parents.

The third generation, many of whom know very little of their family's original language, frequently returns to their ethnic roots as a kind of boutique ethnicity, as a way of differentiating themselves from their parents, and also as part of the natural alliance of grandparents and grandchildren.

Assimilation takes time. It's not just about information available, or about mobility, or about communication. It's about family dynamics, human psychology, and the pain of leaving home.