The Short Answer
These two look almost identical, and that’s why complimentary and complementary get mixed up so often. The good news: both are real, both are correct—just in different situations. Complimentary is about a compliment (praise) or a courtesy (free). Complementary is about a complement (something that completes or pairs well).
Table of Contents
Core Meanings: Complimentary vs Complementary
Complimentary connects to the noun compliment (a nice remark) and commonly means “praising” or “given free.” Complementary connects to the noun complement (something that completes) and means “finishing,” “balancing,” or “working well together.” If the sentence is about praise or free service, it leans complimentary. If it’s about fit, match, or completion, it leans complementary.
Complimentary: Praise or Free
Complimentary is the word for praise and for something free that’s given as a courtesy. A complimentary comment is a nice remark. A complimentary ticket is a free ticket. This is why you’ll see complimentary around hospitality and customer service: complimentary breakfast, complimentary drinks, complimentary upgrade. ✅Source
- Core idea
- Compliment → complimentary (praise / free courtesy)
- Common nouns nearby
- remark, review, words, ticket, service, breakfast, drink
- Typical tone
- Positive, friendly, appreciative, or customer-focused
- Praising “She wrote a complimentary note about the team’s work.”
- Free “Guests receive a complimentary welcome drink.”
- Courtesy “The venue offered complimentary parking.”
Complementary: Completing or Matching
Complementary describes things that complete each other or go well together. That can be skills on a team, flavors in a recipe, or colors in a design. In color theory, complementary can also mean a paired set of contrasting colors that balance each other visually. If the sentence feels like “these two parts fit,” “they balance,” or “they finish the whole,” that’s complement territory—so it’s complementary. ✅Source
- Core idea
- Complement → complementary (complete / match / pair well)
- Common nouns nearby
- skills, roles, colors, flavors, approaches, features
- Typical meaning
- Two parts that strengthen the same whole
- Skills “Their strengths are complementary, so the partnership works.”
- Design “The accent color is complementary to the main palette.”
- Features “The app has complementary tools that work together.”
Why They Get Confused So Easily
Complimentary and complementary are close in spelling, close in sound, and they share the same “-mentary” rhythm. That’s enough to trip people up in fast writing. The key difference is the base word you’re building from: compliment (praise) vs complement (something that completes). Many dictionaries even flag them as a common mix-up, because it’s that frequent. ✅Source
Word Family: Complement, Compliment, and Their Adjectives
This is where the spelling finally makes sense. Complementary comes from complement, which can mean “to complete or enhance by adding something.” Complimentary comes from compliment, which is about praise. Once you connect each adjective to its root noun, complimentary vs complementary stops feeling random. ✅Source
- Compliment (noun) → a nice remark → complimentary (praising)
- Complement (noun/verb) → a finishing piece / to complete → complementary (completing/matching)
- Complementarity (noun) → the quality of being complementary
Common Contexts Where Each Word Shows Up
If you see complimentary, expect praise or a free perk. If you see complementary, expect a pair that works well together—two parts that complete the same whole. The surrounding nouns usually give it away, even when the sentence is short.
When You’ll See “Complimentary”
- Complimentary remarks, comments, feedback, review
- Complimentary drinks, coffee, snacks, breakfast
- Complimentary tickets, passes, samples
- Complimentary shipping, gift wrapping, parking
When You’ll See “Complementary”
- Complementary skills, roles, strengths
- Complementary colors, tones, shades
- Complementary features, tools, services
- Complementary flavors, ingredients, aromas
Side-By-Side Comparison
| Category | Complimentary | Complementary |
|---|---|---|
| Main meaning | Praising or free as a courtesy | Completing, matching, or working well together |
| Root word | compliment (a nice remark) | complement (a completing part) |
| Common neighbors | review, remarks, tickets, breakfast, drinks | skills, colors, features, flavors, approaches |
| Clean example | “They left a complimentary message after the event.” | “Their skill sets are complementary.” |
| Common mix-up | ❌ Wrong “Complementary drinks” (if you mean free) | ❌ Wrong “Complimentary colors” (if you mean matching colors) |
Spelling Clues That Explain the Difference
In real writing, the fastest clue is the meaning you’re aiming for. Complimentary lines up with compliment (praise) and “free.” Complementary lines up with complement (complete) and “matching.” The letters are doing real work here: i in complimentary goes with compliment. e in complementary goes with complement.
- If it could be swapped with free (no charge), it’s complimentary.
- If it could be swapped with praising, it’s complimentary.
- If it could be swapped with matching, balancing, or completing, it’s complementary.
Examples in Context
Complimentary: Praise
- “He made a complimentary remark about her presentation.”
- “The product received complimentary reviews from early users.”
- “Her email was short, clear, and complimentary.”
Complementary: Completing or Matching
- “Their roles are complementary, not overlapping.”
- “The two tools are complementary—each fills a different gap.”
- “The wall color is complementary to the furniture.”
Common Mix-Ups You’ll See
These mistakes pop up because the phrases sound natural either way—until the meaning is checked. When the sentence is about a free perk, complimentary is the match. When the sentence is about a pair that fits, complementary is the match. The switch usually happens in just a few repeating patterns.
- ❌ “Complementary breakfast” (when it means free) → ✅ “Complimentary breakfast”
- ❌ “Complimentary colors” (when it means matching colors) → ✅ “Complementary colors”
- ❌ “Complimentary skill sets” (when it means completing each other) → ✅ “Complementary skill sets”
FAQ
Frequently Asked Questions
Is “Complimentary” Always About Praise?
No. Complimentary can mean praising, and it can also mean free as a courtesy. Both meanings are standard in modern English.
Does “Complementary” Ever Mean Free?
Not in the usual sense. Complementary is about completing, balancing, or matching. “Free” is typically complimentary.
Which One Goes With “Colors”?
In design and color theory, the standard phrase is complementary colors—colors that work together as a pair.
Which One Goes With “Tickets” or “Breakfast”?
If the meaning is “given free,” the standard wording is complimentary tickets or complimentary breakfast.
Can People Be “Complementary”?
Yes. People, personalities, or working styles can be complementary when they balance each other and make a stronger team together.
What’s the Easiest Memory Hook?
Complimentary contains compliment (with an i)—think praise. Complementary contains complement (with an e)—think complete.