Forums or Fora
I must confess that I do not like the automatic spell-checker or the dictionary feature of Microsoft Word. The other day as I repeatedly typed the word fora, a space would surreptitiously creep in before ‘a’ and my fora would look like for a. I tried to correct it and each time as I pushed ENTER for the next word, fora would become for a again! I found it extremely irritating. Yet, as I have learnt English in India, that too more than forty years ago, I had to turn to some of the modern authorities of the English language to check if I made an error.
The word forum is derived from the Latin word of the same spelling meaning enclosure surrounding a house and by extension it referred to an ancient Roman marketplace, especially a place of assembly or judicial and other business. In fact, the Latin forum is related to forés which signifies (outside) DOOR. So the closest kin of the word forum in English is foreign — “out of doors” and thus “pertaining to another, alien”. In modern English, the word forum primarily means a meeting or medium for an exchange of views and especially in North America it also indicates a court or tribunal (COD).
Fora is the valid plural form of forum in Latin. However, in English the preferred form now seems to be forums and not fora. In his Modern American Usage Bryan Garner explains so adding that “some writers, especially in political science and law, persist in using the pedantic fora.” For words imported into the English language from other languages such as Greek and Latin, Garner’s recommendation is: “….if it’s a close call, use the native plural.” So, according to him, “It’s pedantic and prissy to say that politicians attend fora”.
It seems that for Latin words that have been thoroughly and completely naturalized, the English plural with an additional s is preferred. But for words rarely used in English or where the foreign plural form has been established in English long ago, those forms are retained and perhaps still preferred(crisis-crises; criterion-criteria).