One day, a handsome prince hacked his way through some vines (ruining his fine sword) and
discovered the princess in the tower. He called up to her and told her not to worry—he would
find a way to rescue her. She cheerfully yelled down that there was no need. She had figured
out how to unlock the tower years ago, and now that something exciting had happened,
she was ready to leave. The prince was a bit nonplussed by this, but recovered (and started
preening) as he saw her striding towards him with a beaming smile on her face. Maybe it’s a
good thing that he didn’t know what she was thinking.
___
Dear Diary,
Today something exciting finally happened. I got to meet a horse! He isn’t like the horse that
is in my picture book. He is gleaming white, rather than being black all over. The horse is very
nice—not at all like those girl-eating horses that the witch described to me. Oh, and I met a
boy, too! He said I could decide which path to take. I was so happy to choose! I asked him,
“What’s at the end of the path that follows the river?” He told me it led to his castle. It turns
out that he is a prince! Then I asked him, “What’s at the end of the path that goes over the
big hill?” He told me there was a town, and they were having a festival today. I’ll bet you can
figure out where I went!
___
Our resourceful princess finally got to use that instead of which. She needed her reader
to understand that the white horse was not the same as the horse in the book or the
horses described by the witch. The reader also needed to know which of the two paths the
princess was describing. All of the information is essential, so nothing can be eliminated.
(That’s why the information is not surrounded by commas.) Otherwise, we’d have this
wonderful nonsense:
___
Dear Diary,
Today something exciting finally happened. I got to meet a horse! He isn’t like the horse
that is in my picture book. He is gleaming white, rather than being black all over. The horse
is very nice—not at all like those girl-eating horses that the witch described to me. Oh,
and I met a boy, too! He said I could decide which path to take. I was s