Well first I just left as an Au pair. It was suppose to be only for a year!!
Then I decided to change my visa to a student visa after a year and to go back to school! (Don't worry mom I'm coming back in just 3 little years!!)
I didn't plan on meeting that wonderful guy who would become my husband last September.. Bye bye all plans to go back in Belgium.. (Sorry mom!)
Anyway, I'm totally in love with California and wouldn't move back to Belgium even if my husband was ok with it!
I totally understand your brother. It can be a little nerve racking especially at the beginning. New place, new people, new language, new culture!
I had a little of a hard with the language to begin with but you get over it. I guess it depends how is English is to begin with. It might seem weird but even though American culture is very similar to ours, it's still different. Especially when you live there!! Some people adapt easier than others.
If I had only one advice, it would be to try to make friends asap. It's easier when you don't isolate yourself!
Good luck to him!!