how do you handle such a person-- lonely,not talking to anyone in class...???

I used to be this way when I was going to college. I am trying to think of what I would have wanted. I appreciated it when people said hello to me and took a personal interest. I also had at the time, roommate issues, that were on the forefront of my mind, and didn't talk because there was nothing positive to say, as well as that I didn't have people skills or the ability to relate to pop culture. I answered a lot of questions in Spanish. Am sure that the other students started not liking me for that. I would say just be friendly, include the person when you can. Don't make a big deal out of the way they are. When there is a need and a reason, they may change to be different.

Although I agree that this person may just be shy or lack social skills, there is still room for people to worry about someone who seems anti social to that degree. The shooters at Columbine high school and Kent State University were all anti social. I would keep an eye on this person in case he/she shows more signs of a troubled life.

just leave the person alone and let them get on with their studies without being distracted as it seems to me this is what they want to do

i used to be like that, i didn't talk to anyone while in the class so that i can concentrate but i used to talk when out of the class, i sometimes used to talk in the class while i am sitting near my best friend