Jacon Katz, aged 7, of Toronto, Canada, for his question:

Why do some words have commas in them?

In reading, we often come to a word with a comma between the letters. It looks as if the comma sits up there to take the place of a letter. And in a way it does. Fashions change in almost everything. They even change in writing and speaking. There was a time when letters were used in place of those commas.

In days of long ago, people did not say, Peter's hat, or Jacob’s coat when they meant the hat belonging to Peter and the coat belonging to Jacob. They said Peter, his hat and Jacob, his coat. Try saying that fast and see how it sounds, It sounds like Peter’s hat and Jacob’s coat.

To write it that would be confusing. Also, in writing we try to be as careful and accurate as possible. It was necessary to show that certain letters has been missed out. That is what the comma is doing up there in Peter's hat; host commas in the middle of words are there to show that some letters have been dropped. They are galled apostrophes,