Add Yahoo as a preferred source to see more of our stories on Google. People say it every day without thinking ― “two o’clock,” “six o’clock,” “eight o’clock sharp.” But what is the purpose of that ...

People say it every day without thinking ― “two o’clock,” “six o’clock,” “eight o’clock sharp.” But what is the purpose of that little “o” and apostrophe? Is it short for something? Why do we only use ...