“You Complete Me!”

English occasionally produces word pairs that seem too neatly matched to be accidents. Compliment and complement are one of those pairs. Most dictionaries will tell you they are simply different words with different histories that happen to sound alike. That is true as far as it goes. Yet when you look at how the words function, something more interesting emerges.

A compliment is an expression of praise or admiration. A complement is something that completes, enhances, or fills out something else. At first glance, those definitions seem unrelated. One belongs to the world of people and conversation; the other belongs to systems, objects, and relationships. But the more closely you examine them, the more they appear to perform the same underlying job.

They are what I have been calling homophonyms (words that sound alike, are spelled differently, and occupy similar conceptual roles despite arising from different origins). Unlike ordinary homophones, which merely share pronunciation, homophonyms seem to rhyme conceptually. Their meanings are not identical, but they operate on parallel planes.

What makes this pair particularly interesting is that neither is strictly necessary. A meal can be eaten without a side dish. A machine can operate without an accessory. A person can go through his day without receiving praise. Yet both words often describe something that functions as lagniappe—a little something extra, a bonus, an unexpected addition that was not required but makes the whole experience better.

Consider what happens when you give someone a sincere compliment. You are providing recognition, appreciation, or affirmation. The recipient did not need those words to continue existing, but they often enhance the moment. Sometimes they do even more than that. Sometimes they fill a social or emotional gap the person did not realize was there. A compliment can be mere lagniappe, or it can complete something that was missing.

A complement performs the same function in a different domain. A side dish complements a meal. A business partner complements another partner’s weaknesses. A good wine complements a dinner. None of these additions are necessarily required for the thing to exist. Yet they improve it. In some cases they transform it from merely adequate into complete. A complement may begin as an enhancement and end as a completion.

That parallel is what makes this pair so fascinating. A compliment enhances or completes a person emotionally, while a complement enhances or completes a thing functionally. One operates in the realm of human relationships; the other operates in the realm of practical relationships. They are not the same word, and they are certainly not interchangeable, but they seem to share the same conceptual architecture.

The next time someone compliments your work, consider the possibility that he is doing more than offering praise. In a small way, he is complementing it as well. Both words describe something extra. Both words describe something that enhances. And on occasion, both describe the final piece that turns something good into something complete.