In the first 48 hours our group arrived in Chile before we met our host families, they were all we could talk about. Everyone was excited and nervous and anxious, myself included. I can say now though that living with a family was a great experience, and I'm glad CIEE makes it mandatory for everyone in our program.
On just an immersion level, living with a Chilean family is very effective. It really forces you to use Spanish, and to learn to express yourself, especially in situations where you may not have the vocab or grammatical structures to say what you want and have to figure out how to work around those difficulties. In terms of day-to-day issues, it would have been really difficult to do things like figure out how to navigate public transportation or how to get cold medicine without having a family to ask.
Additionally, living with a family taught me a lot about Chilean culture first hand. I got to eat home-made food every day, and tried traditional foods like empanadas, humitas, pastel de choclo (a corn dish), cazuela de ave (a chicken soup dish), and others, especially some interesting seafood, some of which doesn't even have an English translation, including mussels, oysters, cochayuyo (a rubbery seaweed), and locos (type of sea snail). I got to go to the weekend market and experience first hand why all the produce is so fresh and delicious. I got to meet family friends and learn even more about everyday Chilean life.
Most of all, my family took care of me. Of course it was a little awkward in the beginning, but I felt like I really fit in and was part of the family. My host mom, Margarita, put me at ease right away, always asked about my day, and was ready with food or ideas whenever I asked (and even sometimes when I didn't). My host dad, Pancho, didn't say much but was always ready to give me his opinion on things, tell me to take care of myself and behave when I went out at night, and give me a hard time the next morning. My host sister, Paula (age 26), is absolutely adorable, and it was really fun having a sister for the first time. We helped each other with homework (she was taking a post-grad class) and would chat about clothes, and she was always there to help out if my mom wasn't around.
I still keep in touch with my mom and sister - my mom even sent me a happy birthday email 2 months after the end of the program! I like knowing that they made a big impression on me, and vice versa. I can't wait to go back there and see them again one day!