Here's a quick explanation of the general rules about the words alright, all right, OK, and okay.
Alright vs All right
- In formal or professional writing (such as business writing and academic writing), the standard "all right" should be used.
"All right" is the original term. As such, it can never be incorrect. The term "alright" emerged later as a variant of the phrase. It could be argued that other English phrases such as "all together" and "all ready" have made the shift to "altogether" and "alright". Therefore, "alright" should be equally valid.
This is a good point for the acceptability of alright. Nevertheless, as a general guideline, professional writing still tends to avoid it in favor of the standard all right.
References
- All Right or Alright: Which is correct, and when? (n.d.) Merriam Webster. https://www.merriam-webster.com/words-at-play/all-right-or-alright-which-is-correct
- Guffey, M. R. (2013). Canadian Business English (6th ed.). Nelson Education.
OK vs. Okay
Both words have the same meaning. Surprisingly, OK is not an abbreviation (shortened form) of okay. Historically, O.K. was an acronym that stood for a purposely misspelled "all correct" (read the full story here). Later, "O.K" became more popular when it was adopted as part of the campaign slogan of a U.S. politician Martin Van Buren, who was also known as "Old Kinderhook."
Van Buren was OK (Ol' Kinderhook).
OK or Okay: Which is more formal?
Neither word is formal. In academic or professional writing, I'd recommend finding a more standard English word (e.g. acceptable, satisfactory, fine) than using a phrase that, after all, started as a joke.
With that said, in business writing (especially e-mails), writing concisely (briefly and clearly) is important. When high formality is not needed, OK is a useful shortcut.
Which is the standard spelling?
According to the Merriam Webster dictionary, OK is the standard spelling of the word. This makes sense because okay was derived from OK (i.e. it came later).
In summary, both words are fine, but an argument could be made that OK, as two letters, is more historically accurate than the spelling okay.
References
- Brewer, R. L. (2019, August 26) OK vs. Okay (vs. O.K.). Writer's Digest. https://www.writersdigest.com/write-better-fiction/ok-vs-okay-vs-o-k
- Klein, C. (218, August 31). The Birth of OK, 175 Years Ago. History. https://www.history.com/news/the-birth-of-ok-175-years-ago
- OK. (n.d). Merriam Webster. https://www.merriam-webster.com/dictionary/OK
- Written by Matthew Barton of EnglishCurrent.com