Complement/Compliment, Principal/Principle, Stationary/Stationery

Three pairs of words that sound the same but mean completely different things. A spellchecker won't save you — every one of these is a real word — so the only defence is knowing which is which. The good news is that each pair has a little memory trick that settles it for good, and once it clicks you won't un-know it.

complement vs compliment

• complement (with an e) = something that completes or goes well with something else. The scarf complements her coat. Fries complement a burger.
• compliment (with an i) = a nice thing you say (or, as a verb, to say it). She paid me a compliment. He complimented my drawing.

Trick: complement with an e = it completes. compliment with an i = "I like your shoes!" — a nice thing I say.

Watch it in action:

• ✗ Thanks for the lovely complement. → ✓ Thanks for the lovely compliment. (something nice you said)
• ✗ The music compliments the film. → ✓ The music complements the film. (it completes it, goes with it)

There's also a free twin to watch: complimentary can mean "kind" (complimentary remarks) or "free of charge" (a complimentary drink) — both grow from the "nice thing given" idea.

principal vs principle

• principal = the main one, or the head of a school or organisation. The principal reason. The school principal. The principal dancer.
• principle = a rule, a belief, or a scientific law. It's against my principles. The principle of fairness. The principle behind the engine.

Trick: the principal is your pal — a person (the head teacher). A principle is a rule — both end in -le.

Watch out:

• ✗ It's against my principals. → ✓ It's against my principles. (my rules and beliefs)
• ✗ The principle asked to see us. → ✓ The principal asked to see us. (the head — a person, your pal)

stationary vs stationery

• stationary (with an a) = not moving, standing still. The car was stationary in traffic.
• stationery (with an e) = paper, pens and envelopes — writing materials. I bought some stationery for school.

Trick: stationary = at rest (with an a). Stationery = envelopes and pens (with an e).

Watch out:

• ✗ The bus stood stationery at the stop. → ✓ The bus stood stationary. (not moving — a)
• ✗ We ran out of stationary in the office. → ✓ We ran out of stationery. (pens and paper — e)

Two bonus pairs, same idea

Once you're tuned in, you'll spot more sound-alikes that work in exactly the same way:

• desert vs dessert. A desert (one s) is dry sand — the Sahara. A dessert (two ss) is the sweet course after dinner. Trick: dessert has two ss because you always want second servings of pudding.
• brake vs break. You brake to stop a bike; you take a break at lunch, or break a glass. Trick: a brake on wheels shares its -ake with lake and cake — machine words; break is the odd one out.

Different words, same defence: one real word looks like another, so you learn a tiny picture that keeps them apart. Collect a trick for each pair you personally mix up, and your "silly mistakes" quietly disappear.

Why these are worth a memory trick

Homophones like these are the classic "silly mistake" that costs a mark — not because you didn't know the idea, but because two real words look alike and you were writing quickly. The tricks above take seconds to learn and turn a coin-flip into a certainty. Pick the one image that sticks for each pair — "I" for a compliment, "pal" for the principal, "e for envelopes" — and you've locked all three for good.

A quick way to remember all three

Notice that in every pair, the e spelling points to the "completing / writing / rule" meaning you might not expect, while the everyday-looking word is the common one. When you're unsure, slow down for half a second and picture the trick — that pause is the whole skill. Nobody expects you to never meet these words; they just expect that when you do, you stop and choose rather than guess. Do that a few times and the right spelling starts coming automatically, no trick needed.

Quick check

Choose the right one:

1. Thanks for the lovely ___ (complement / compliment).
2. My ___ is that everyone should be treated fairly (principal / principle).
3. The train sat ___ at the platform (stationary / stationery).
4. This blue tie really ___ your jacket (complements / compliments).
5. Our head teacher — the ___ — spoke in assembly (principal / principle).
6. I need new ___ : pens, paper and a ruler (stationary / stationery).

Answers

1. compliment ("I" said something nice)
2. principle (a rule — ends in -le like rule)
3. stationary (at rest — with an a)
4. complements (it completes/goes with the jacket — e)
5. principal (the head — your pal)
6. stationery (envelopes and pens — e)

Where next

• Their, There or They're? — the most famous sound-alike trap.
• Affect or Effect? — another pair one letter apart.
• Commonly Confused Words — the full list, with a trick for each.