Dear SPOGG: The word "that" is used more and more and in instances where I believe the correct word should be "which". I thought the words were determined by animate or inanimate objects. Please correct me.
— Nan M.
Dear Ms. M:
Please correct you? OK, then. We will. Use which when you're setting a clause off with a comma. Use that when you're not.
To find out why, read our "Doctor, she's in a comma" post.