Know, close to five years. is it possible that a person can forget their native language, either through trauma that bergdahl endured, or through lack of use, if he was communicating with his captors through another language? >> i can't speak to the trauma. i'm not a psychologist. but i can tell you that linguists have studied this phenomena called language attrition, for quite a few years. we're learning ever more about it. the quick answer is, he hasn't forgotten it. the chances are overwhelmingly in favor of him retrieving his english quite quickly. people do this all the time. we've had st...