Refine By

Commonly misused words

Some words seem so alike that they’re easy to mix up. Even the best writers get confused sometimes. So here’s a list of frequently mistaken words and phrases – and how to use them correctly.

Capital & capitol

“Capital” is a sum of money (usually used when talking about investment), an uppercase letter, or a seat of government. “Capitol” is a building housing said government’s legislative body.

Check in, checkin & check-in

“Check-in” (with a hyphen) is a noun. It’s the place or time you check in, whether online or in the real world.

“Check in” (without a hyphen) is a verb. It’s what you do at check-in.

Don’t use “checkin” as one word.


  • Our app makes check-in effortless.
  • It’s effortless to check in with the app.

Check out, checkout, & check-out

“Check out” (without a hyphen) is a verb. It’s what you do at check-out.

“Check-out” (with a hyphen) is a noun. It’s the act of checking out of the hotel, or the time when you check out.

“Checkout” is the cash register or the web page on which you pay for the room you’ve booked.


  • Check out at the checkout counter at check-out time.

Complementary & complimentary

The word “complementary” describes things that complete or enhance one another. “Complimentary,“ on the other hand, is a synonym of “free,“ which also means “expressing praise or admiration.”


  • Chef Heinz Beck is renowned for pairing complementary flavors.
  • Begin your meal with complimentary champagne and canapés.
  • Diners are often complimentary about the restaurant’s impeccable service.

Contemporary & modern

“Contemporary” is not synonymous with “modern.” When used to mean modern, “contemporary” carries a negative connotation of blandness. It simply means “from the same time frame.”


  • Set in the converted 17th-century residences of Amsterdam’s Grand Merchants, the Waldorf Astoria Amsterdam features contemporary artwork from the 17th century.

Coordinate & coordinator

Use “coordinator” as one word. Avoid “co-ordinator” or “co ordinator.”


Our wedding coordinator will ensure your day goes without a hitch.

Definitely & defiantly

“Definitely” means “without a doubt” or “clearly.”

“Defiantly” means “with open resistance or disobedience.”


  • “I would do anything for love, but I definitely won’t do that,” said Meat Loaf defiantly.

Discreet & discrete

“Discreet” describes something delicate, unobtrusive, or private.

“Discrete” describes something separate and distinct.


  • Housekeeping is efficient and discreet.
  • The Waldorf Towers is discrete from the Waldorf Astoria New York.

i.e. & e.g.

These abbreviations come from Latin:

  • e.g.: exempli gratia, meaning “for example.”
  • i.e.: id est, meaning “it is”

Use a period after each letter, but no space. Always follow either with a comma. It’s often best to use them in parentheses, but that isn’t a hard-and-fast rule: they can also be used following a comma.  Capitalize them only at the beginning of a sentence or in a title – where they generally shouldn’t occur unless you’re talking about the terms themselves.

The abbreviations are common in English, so we do not italicize them. However, the words are uncommon, so they should be italicized.

Webcomic the Oatmeal offers an entertaining guide on when to use “ie” and “eg.”

OK, O.K., & okay

The origins of “OK” as a term are murky at best, but the consensus is that it’s an acronym that’s become a word unto itself. Use only “OK.” 

On-site, on site, & onsite

“On-site” is an adjective. It comes before the noun it describes.

“On site” is a prepositional phrase. It comes after the noun it describes.

“Onsite” is not a thing, but it looks like the name for a pretty rock.

It’s preferable to use the two-word version, to avoid confusion regarding hyphen use.


  • Avoid: Onsite parking
  • Try: On-site parking
  • Try: Parking on site

That & who

“Who” refers to people. “That” refers to anything else.

This is a common mistake to make in spoken English, so you may need to pay close attention to notice it in your writing.

Avoid: Feel free to pick up a keycard for any other guest that needs one.
Try: Feel free to pick up a keycard for any other guest who needs one.

Would’ve, could’ve, & should’ve

All three of these words are contractions. Spelled out, they are “would have,” “could have,” and “should have.”

Do not spell them as “woulda,” “coulda,” “shoulda,” or “would of,” “should of,” “could of.”