Don’t forget to pack your diphthong to the beach

By Curtis Honeycutt

I promised myself that I wouldn’t mention Sisqo’s 1999 hit “Thong Song” in this article, but I’ve already done it. Avid Grammar Guy reader and fellow word nerd Dan sent me the following message: “Please help me clarify if a diphthong is a part of grammar, or something worn to take a dip in the pool.” Today I’m happy to tackle Dan’s scantly covered topic.

Whether you rock a Speedo, tankini or three-piece suit to the beach, it’s important to know about the diphthong. It is not, in fact, a cheeky piece of swimwear or underwear; in reality, a diphthong is a grammatical term.

The word “diphthong” comes from the Greek word “diphthongos,” which means “having two sounds.” You’ll recognize the Greek prefix “di-,” which means “two,” and the word “phthongos” which translates to “voice” or “sound.” “Phthongos” is where we ultimately get the word “tongue.”

Diphthongs deal specifically with two vowel sounds that appear back-to-back in the same syllable of a word to create two distinct vowel sounds. Examples include “oil,” “town” and “light.” Sometimes diphthongs can be subtle, but the moving vowel sounds are there if you speak the words aloud. If a word, conversely, has a static vowel sound, that sound is called a “monophthong.”

Some experts opine there are 10 diphthong sounds in the English language, but most agree that there are eight. The first makes an “eye-ee” sound, as in “lime” and “bike.” Secondly, we have an “ay-ee” sound, as in “great” and “rain.” As I said, some diphthongs are subtle (like the “b” in “subtle”). Next, we have an “uh-oh” sound, as in “boat” and “though.” Fourth is the “a-oh” sound, as we hear when we say “brown” and “cow.” The fifth English diphthong is “ay-uh,” as in “air” and “bear.” The “ee-uh” diphthong sound appears in words including “beer” and “pier.” The penultimate diphthong is “oh-ee,” as in “boy” and “oil.” Finally, we have “oo-uh,” as in “sure” and “lure.”

While I’m not a linguist, diphthongs are often written in linguistic marks, as you find in the dictionary after each word’s entry. While it may seem like Greek to you or me, knowing your way around English diphthongs beats having a piece of thin material wedged uncomfortably up your posterior, so to speak. So, if we do get the chance to travel to the beach in 2021, make sure to pack all eight of your diphthongs, one for each day of the week (plus a spare in case you’re feeling bare).

—Curtis Honeycutt is a syndicated humor columnist. He is the author of Good Grammar is the Life of the Party: Tips for a Wildly Successful Life. Find more at