Compound words sometimes don’t have the same meaning as the individual words they comprise. It’s a case of the whole being different from the sum of its parts. Everyday and every day are like that—everyday (with no space) doesn’t mean the same thing as every day (with a space). In speech, however, they do sound the same. No wonder it’s so easy to confuse them with each other. What does each phrase mean and how do you use them?