When I came to America 15 years ago, I was convinced that in order to succeed here I would need to go through a process of learning and sharing some common cultural values; I knew from the start that communication would be the key. I was training as a sociologist, and I had a job with Foster Parents Plan International, which needed a speaker of Spanish and Portuguese. I didn't speak any English, though. I couldn't even go into a restaurant and order a meal. I felt people were looking down on me. I had two choices: Go back, or learn to speak English. I quit my job after six months and enrolled in an immersion course. I gave myself six months to learn English. It took me three years, and during that time I was finishing my education.

The first year was frustrating. I never really felt isolated, but I like to talk. I was ready to use sign language, anything.

Both my children are bilingual. They were born here. My son, who's 11, says, "I'm an American. I'm not really interested in going to Bolivia." I don't try to force the issue, but I always remind him where he's from. I talk about our culture and our ancestors. You can't change what you are. That's your identity. You have to be proud of it.

We also talk a lot about American history. It's been important to me to research the social and historical events that shape this society.

Many immigrants don't make an effort to invest in America. They want to make some money and think they will go back. That mentality is really terrible. You hurt yourself, your family, the whole community. We have to have a commitment. I've always asked myself: How can I be part of this society? Now I'm trying to push others to do the same.

Percy Calderon, 42, is a naturalized U.S. citizen from Bolivia.