A de facto guide to Latin words in English 

(Level B2 and above: Latin words commonly used in the English language)

Written and compiled by Benedicte Gravrand, The Language House.

The English language has West Germanic origins, but still, about 60% of English words have roots in Latin and Greek.

A Latin root such as “ann” (yearly) gives you annual, “aqu” (water, sea) gives you aquatic, “bene” (good) gives you beneficial, “bi” (two) gives you biceps, “circum” (around) gives you circumvent (getting around a problem); “clar” (clear) gives you clarity. And so on.

Many Latin words are used in their original form in many languages, including English. Here are some that are used quite commonly in the English language – and very often in legal English:

  1. Bona fide (adj/adv): genuine, real. She was a bona fide expert.
  2. Modus operandi (noun): the way something operates or works. Also known as M.O. Every killer has his own special modus operandi.
  3. Ad hoc (adj): done when needed for a specific purpose. ...ad hoc committees to examine specific problems.
  4. Ad nauseam (adv.): if you do or say something ad nauseam, you repeat it so many times that it annoys other people. We discussed it ad nauseam.
  5. Caveat (noun): a warning of the limits of a particular agreement or statement. I’ve given it to them, but with the caveat that it didn’t work. Caveat emptor: “buyer beware” – when you buy something you are responsible for checking its quality.
  6. Circa (prep): used before a date or number for showing that it is not exact. Circa is usually written simply as c. A story set in France circa 1660.
  7. Compos mentis (adj): able to think clearly, sane.
  8. De facto (adj/adv): actual, even though not official. English is the de facto language of the computer industry.
  9. Ergo (adv): Therefore. Neither side would have an incentive to start a war. Ergo, peace would reign.
  10. Erratum (noun): a mistake in a book that is discovered after it was printed and is then corrected in an added list. Plural: errata.
  11. Per (prep): used for stating the rate or cost for each unit of time, quantity, distance etc. He is paid £10 per hour for the job. (per annum: for each year / per capita: for each person / per se: in itself – It is not the money per se that makes them unhappy…)
  12. Post-mortem (noun): autopsy. The post-mortem revealed that she had been murdered. (post: after – a post-impressionist painting).
  13. Pro rata (adj/adv): calculated according to the individual situation. Holiday entitlement for part-time staff is calculated pro rata (=according to the number of hours worked).
  14. Quid pro quo: something that you offer or give to someone in return for something that they have offered or given you. They share a great deal of information on a quid pro quo basis.
  15. Sine qua non (noun): a condition that must exist before something can happen. Successful agricultural reform is also a sine qua non of Mexico’s modernisation.
  16. Status quo (noun): The state of affairs that exists at a particular time. The federation voted to maintain the status quo. (Status: the legal position of a person, country, etc. Manuel applied for legal immigrant status after living here for two years.)
  17. Terra firma (noun): land, especially as compared with water or air.
  18. Verbatim (adj/adv): repeating the exact words that were used. The article repeated our press release almost verbatim.
  19. Versus ( vs. / v.) (prep): compared to. The US dollar fell versus other key currencies on Friday.
  20. Vice versa (adv): the opposite of what has been said. Should I come to your house or vice versa?
  21. Persona non grata (noun): someone that people do not like or welcome. He was declared persona non grata by the team.
  22. id est (better known as “i.e.”): that is. Senior officers – i.e. anyone with the rank of colonel or above – get their own administrative staff.

Sources: Englishclub.com; MacmillanDictionary.com; CollinsDictionary.com


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Latin email

Here is an email a businessman sends to his colleague after negotiating a partnership deal with another company. As you will see, he really likes his Latin words.

So I’m flying back home at the moment, but once I am on terra firma, I’ll make sure to send you a post-mortem of the failed negotiations. We could not reach an agreement on a quid pro quo basis, and that is a sine qua non of any commercial partnership agreement. We could not even agree on pro rata payment terms per annum. It was very much our company versus theirs. The status quo remains. They didn’t cooperate and vice versa.

While I was there, I really tried to remain compos mentis while we were discussing the same commercial terms ad nauseam. We kept on quoting our proposed contracts verbatim. It was really hard. I think we should think of them as a de facto uncompliant company. Their M.O. is to refute all suggestions, whether they be ad hoc or not. They’re bona fide reactionaries.

We could try again, though with a different negotiator as I may now be persona non grata, with the caveat that it won’t work, again. Neither side wants to give in, ergo restarting the negotiations would be futile. It is not partnering with another company per se that they are opposed to, it is partnering with our company.


Erratum: we forgot to include et cetera (etc.) and exempli gratia (e.g.) in the list of Latin words, though they do not need an introduction.


Garry Littman

Garry Littman est le fondateur de The Language House à Genève. The Language House propose des coachings d'anglais à Genève pour les particuliers et les entreprises, ainsi que des cours intensifs d'anglais dans les pays anglophones. Garry a été journaliste en Australie et en Asie, il a travaillé pour World Radio Switzerland.

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