Complement vs Compliment: What's the Difference?

A compliment (with an i) is a remark of praise: She paid me a lovely compliment. A complement (with an e) is something that completes or goes well with something else: The sauce is the perfect complement to the fish.

Both words can also be verbs, and both have adjective forms (complimentary and complementary) that cause even more confusion, partly because complimentary also means "free." They're pronounced the same, so the difference lives entirely in the spelling. Here's how to keep them apart, from restaurant menus to grammar textbooks.

Quick answer: Compliment = praise. Thanks for the compliment! Complement = complete, go well with. The wine complements the cheese. Complimentary also means free: complimentary Wi-Fi.

On this page

1. Compliment: Praise (and Free Things)
2. Complement: Completing and Matching
3. Complement vs Supplement
4. Complimentary Close and Other Formal Uses
5. One Letter, Two Histories
6. Pronunciation
7. At a Glance
8. Example sentences
9. US vs UK vs Australia
10. Errors That Keep Coming Up
11. Two Tricks That Work
12. Practice quiz
13. A Practical Habit

Compliment: Praise (and Free Things)

As a noun

A compliment is an expression of admiration or approval.

• That's the nicest compliment anyone's given me all week.
• He has a habit of fishing for compliments.
• A backhanded compliment is one that sounds like praise but carries an insult: "You look great for your age."

In the plural, compliments can mean formal good wishes or respect: With the compliments of the management, My compliments to the chef, Give my compliments to your parents. These are a little old-fashioned but still widely understood.

As a verb

To compliment someone is to praise them.

• The judge complimented the young barrister on her preparation.
• Several customers complimented the new menu.

The typical pattern is compliment someone on something.

The adjective complimentary

This is where the word gets interesting. Complimentary has two meanings:

1. Expressing praise: The reviews were extremely complimentary.
2. Given free of charge: complimentary tickets, complimentary breakfast, complimentary parking

The "free" sense developed from the idea that a gift given "with compliments" was a courtesy, offered at no cost as a mark of respect. Over time complimentary came simply to mean "free," especially in hospitality and events.

Complement: Completing and Matching

As a noun

A complement is something that completes another thing or makes it better when the two are combined.

• Fresh mint is a great complement to lamb.
• Her calm style is a good complement to his energy.

It can also mean the full number or quantity needed: a full complement of staff, the ship's complement (its full crew).

As a verb

To complement something is to complete it or go well with it.

• The rug complements the curtains perfectly.
• The two job candidates have skills that complement each other.

The adjective complementary

Complementary means combining in a way that improves or completes. It has several technical uses:

• complementary colors: pairs that sit opposite each other on the color wheel, like blue and orange
• complementary angles: two angles that add up to 90 degrees (supplementary angles add to 180)
• complementary medicine: treatments used alongside conventional medicine (in British and Australian usage especially)
• complementary DNA: strands whose bases pair with each other

None of these meanings involve praise or freebies. They're all about two parts fitting together.

Complement in grammar

In grammar, a complement is a word or phrase that's needed to complete the meaning of a verb, adjective or other word. The most common type is the subject complement, which follows a linking verb like be, seem or become:

• Jo is a teacher. ("a teacher" completes is)
• The soup smells delicious.

There are also object complements (They elected her captain) and complements of adjectives (afraid **of spiders). Every one of these uses takes the e spelling because it's about completing, not praising.

Complement vs Supplement

A useful way to sharpen the meaning of complement is to compare it with supplement, a word people often use in the same sentences.

• A complement completes something or makes a balanced whole. The two parts work together, and each is improved by the other. The side salad is a complement to the steak.
• A supplement is something added on top, often to make up for a shortfall. The main thing could stand alone; the supplement simply adds more. Vitamin D supplements, a newspaper's weekend supplement, a single-room supplement (an extra charge).

So training that complements on-the-job learning fills gaps and fits with it, while training that supplements it adds extra on top. The difference is subtle, and in many business sentences either would work. But compliment never belongs in this group, because it's about praise.

Complimentary Close and Other Formal Uses

In letter writing, the complimentary close is the polite phrase before your signature: Yours sincerely, Kind regards, Best wishes. The term uses complimentary in its original "courteous" sense, not the "free" sense. You'll see it in business-writing guides and secretarial handbooks in all three countries. For modern options, see our guide to email sign-offs beyond "Best regards".

Similarly, a compliments slip is a small printed note, common in British and Australian offices, that goes with documents or goods and says "With compliments" alongside the company's name. It's a courtesy, not a free gift, and it always takes the i spelling.

One Letter, Two Histories

Both words come from the same Latin source: complēre, "to fill up, to complete." From it came the Latin noun complementum, which entered English in the late Middle Ages as complement, meaning something that completes.

Compliment took a detour. The same Latin root passed into Italian as complimento and Spanish as cumplimiento, where it came to mean an act of politeness, the "fulfilling" of courtesy. French borrowed it as compliment, and English took it from French in the 1600s. So a compliment is, historically, a social "completing" of good manners.

The two words were sometimes spelled interchangeably in earlier centuries. The modern split, with e for completing and i for praise, became standard over the 1700s and 1800s.

Pronunciation

As nouns, both are pronounced KOM-pluh-ment, with stress on the first syllable. As verbs, many speakers in the US, UK and Australia give a little extra weight to the last syllable (KOM-pluh-MENT), but the two words still sound identical to each other. There's no audible clue, so spelling is everything.

At a Glance

Example sentences

Everyday

1. Thanks for the compliment on my haircut; I wasn't sure about it.
2. A squeeze of lemon is the perfect complement to grilled prawns.
3. Our hotel in Hobart offered complimentary breakfast every morning.
4. That scarf really complements your coat.
5. My grandmother always compliments the cook, even when it's takeaway.
6. We got complimentary tickets to the match through work.

Workplace and email

7. Hi Leah, I just wanted to pass on a compliment from the client about your presentation.
8. Ravi's analytical skills complement Megan's creative approach.
9. All attendees will receive a complimentary copy of the report.
10. The new hires bring the team up to its full complement.
11. Customer feedback has been overwhelmingly complimentary.
12. The training course is designed to complement, not replace, on-the-job learning.

Academic

13. The two theories are complementary rather than competing.
14. Angles A and B are complementary, so together they measure 90 degrees.
15. In "The meal was cold," the adjective "cold" functions as a subject complement.
16. Each DNA strand has a complementary sequence on the opposite strand.

News-style

17. The minister complimented emergency crews on their response to the floods in Lismore.
18. The new bypass is intended to complement the existing rail line.
19. Reviews of the Edinburgh production have been largely complimentary.
20. The hospital is operating with less than its full complement of nurses.
21. Fans praised the team's complementary attacking styles.

Both in one sentence

22. She paid me a compliment on how well my tie complemented the suit.
23. The complimentary wine was a good complement to the meal.
24. His compliment was sincere: our skills really do complement each other.

US vs UK vs Australia

The spelling and the main meanings of complement and compliment are identical in American, British and Australian English. All three use complimentary to mean free, and all three teach complementary angles and colors in school.

The small differences are in collocations:

• Complementary medicine is a very common phrase in the UK and Australia, often paired with alternative (complementary and alternative medicine). In the US, integrative medicine is also widely used.
• "Compliments of the season" is a traditional Christmas greeting more often heard in the UK and Australia than in the US.
• "Comp" as a short form for a complimentary item (the drinks were comped) is mainly American slang, used in hospitality and casinos, though it's understood elsewhere.

Errors That Keep Coming Up

❌ Enjoy a complementary drink on arrival. ✅ Enjoy a complimentary drink on arrival.

❌ The blue cushions compliment the sofa. ✅ The blue cushions complement the sofa.

❌ She gave me a nice complement about my essay. ✅ She gave me a nice compliment about my essay.

❌ The squad has its full compliment of players. ✅ The squad has its full complement of players.

❌ Red and green are complimentary colors. ✅ Red and green are complementary colors.

The most common error is complementary for "free," especially on menus, hotel signs and marketing emails. If you work in hospitality or events, it's worth checking every instance. Signs are read by thousands of people, and this mistake is easy to spot. Other look-alike pairs with a single-letter difference, like principal vs principle and stationary vs stationery, fail in the same way and respond to the same kind of check.

A note for hospitality and marketing writers

Menus, hotel signs, booking confirmations and promotional emails are where the complimentary versus complementary mix-up appears most. A quick way to check: if the item is free, could you write "free" in its place? Free breakfast, free shuttle, free upgrade. If so, it's complimentary. If the sentence is describing how two items pair up (wines chosen to complement each course), it's the e spelling. Many restaurants use both words on the same menu, which makes it worth checking each instance separately.

When both spellings make sense

The trickiest sentences are those where either word produces a real meaning, so a spell-checker or a quick glance can't settle it. Consider these pairs:

• We offer a complimentary car-cleaning service. (It's free.)

• We offer a complementary car-cleaning service. (It goes alongside the main service, such as a car rental, and may well cost extra.)

• The gallery sent a complimentary review copy. (Free.)

• The two critics wrote complementary reviews. (Each covered what the other missed.)

In a customer email, the difference matters: one version promises something at no charge, and the other doesn't. A business in Adelaide or Austin that writes "complementary" when it means "free" may get calls from customers asking why they were billed, and one that writes "complimentary" for an add-on may find customers expecting it for nothing. When the sentence could go either way, ask yourself plainly, "Is this free?" before choosing the letter.

Two Tricks That Work

• "I like compliments." The i in compliment stands for the person receiving praise: I, me, myself. It's also the i in "nice" (a nice compliment) and "free" items you might get without paying, thanks to that extra meaning.
• "Complement completes." Both start with comple-. If you can swap in "complete" or "go well with," use the e spelling.

If you can remember just one, make it the second: complete is literally inside complement.

Practice quiz

Choose the correct word.

1. The chef came out to thank us for our ____ (compliments / complements).
2. The cheese board was a great ____ (compliment / complement) to the red wine.
3. Guests receive ____ (complimentary / complementary) parking at the venue.
4. Two angles that add up to 90° are ____ (complimentary / complementary).
5. His sharp eye for detail ____ (compliments / complements) her big-picture thinking.
6. That was a backhanded ____ (compliment / complement) if I ever heard one.

Answers

1. compliments. Praise passed to the chef.
2. complement. The cheese goes well with the wine.
3. complimentary. Free of charge.
4. complementary. A mathematical term about completing 90°.
5. complements. Their skills complete each other.
6. compliment. A fixed phrase for disguised criticism.

A Practical Habit

Whenever you write either word, ask whether anyone is being praised or anything is free. If so, use the i: compliment, complimentary. If two things are fitting together or something is being completed, use the e: complement, complementary. That quick question will keep your menus, cover letters and emails polished. And if you want to get better at accepting praise as well as spelling it, our guide on how to respond to a compliment has replies for every situation.