When we test and interview new students for the program, one of our "questions" is "tell me about yourself." This question tends to confuse a large number of students, but how they respond to it gives us a lot of information about the students' language skills. If a student has no idea what to say, that student probably belongs in one of our lower-level classes.
A typical response to this question tends to be something like "your what? yourself?" with the student looking at me as if the words "self" or "yourself" are completely alien, which sometimes strikes me as weird...I don't think of either word as all that uncommon. In grad school I used to study things like self-esteem and self-efficacy and I could propose some sort of hypothesis that foreign students have a different handle on notions of self than their American peers, but it really could just be a vocabulary gap. In most cases, there isn't the time (on our part) or the language skills (on the student's part) to go further in these analyses.
Over the ten years that I've been asking new ESL students this question, there has been a change in how the confused students answer this question. I've only just noticed this in the past two years, but sometimes students think I'm saying "Tell me about your cell" instead of "Tell me about yourself" and they start rattling off their cell phone numbers for me. This sort of makes me hate cell phones on a whole new level (though I grudgingly admit that it's a reasonable mistake for the students to make).