1、He's such a nerd, always buried in his books and never socializing with others.

他是个书呆子，总是埋头在书本里，从不和别人交际。

2、I used to be a nerd in high school, but now I've become more outgoing and sociable.

我在高中时是个书呆子，但现在我变得更加外向和善于社交了。