Q. I am a primary teacher. I am currently teaching about compound words and have discovered that I am making errors. Some words that I thought were compound are not. However, when I look them up in different sources or look at signs, they are written both as compounds and closed. Would you please tell me how I can find a list of compound words without looking up each word in the dictionary? Thank you.

A. Although an online searchable dictionary would be a good tool for this purpose, the study of compounds is an awfully advanced topic for primary schoolchildren. Adult writers and copy editors struggle with this issue; I doubt that seven-year-olds can handle it. Most compounds have more than one correct styling. As you’ve discovered, one dictionary will close up words, and another won’t. Even more confusing is that some compounds are hyphenated only when they serve as a modifying phrase. If you must discuss compounds and hyphenation, it would be better to teach your children how to use a dictionary. Show them that dictionaries disagree. Encourage them to use their own judgment in choosing, and then to be consistent. Older children can be taught to read a sentence for sense to see whether a compound benefits from a hyphen.