No he shouldn't. For the very reason I just pointed out. He's struggling learning basic fundamental coding constructs and you are throwing in collections. And in comes me pointing out a concept called type safety, implicit vs explicit type conversion, and boxed and unboxed Objects. There is very little value in telling a student. "I know you're only starting out but here's an advanced concept you might as well pick up."

btw, c# uses dictionaries for generics. small gotcha is a dictionary will throw an exception if they key isn't there, whereas hashtables return null iirc. if this was java, i wouldn't bother mentioning it since generics is just syntax sugar and don't offer runtime benefits, but there are real benefits in .NET