Last week, I looked at what the dictionaries and style guides have to say about the structure x-year-olds, as in We hosted a party for eight 10-year-olds. Those references that listed it used the hyphenated version, but I have a habit of using it without hyphens: 10 year olds.
In my Copyediting III course this past spring, one of my students wanted to know why I had marked on her editing test that 24-year-olds should be 24 year olds. Doesn’t the phrase contain hyphens?
As happens with copyeditors sometimes, I had made the correction reflexively. My thinking was that the x-year-olds form, where x is a number, is a noun, so hyphens aren’t needed. But the student’s question made me stop and think. And I couldn’t answer my student without some research first.
Along with the very common one-letter words a and I, there is the less-common one-letter word O. It came up in conversation during a recent trip to Stratford, Ontario: We couldn’t help but sing in the car O Canada after crossing the Bluewater Bridge. My daughter was the only one among us who knew the rest of the Canadian national anthem (Canada not being our home and native land), and she grumbled that we really needed to watch more hockey.