John, Thanks for this reply and it is helpful. I now understand the concept of the relative clause and its function with regard to sets. The bit on nouns gave some additional insights as well. I would appreciate your indulgence with a follow up question.... Sooo, what makes a relative clause a relative clause? In other words, "how would I know one when I saw one?" :-) I realize it may be the case that the answer to this question is circular (i.e. a relative clause is a clause linked to a noun that partitions the set the noun represents into a smaller subset). However, it would be helpful for me to know if that (the fact that it is circular) is the case or if there is another definition that may apply. Thanks again. This is very helpful. Todd