‘Data is’ or ‘data are’: is it worth fighting over Latin words?

Posted on 24 November 2014 by Lucy Gregory

The other day I witnessed a most pleasing incident: four clients, in a workshop, coming to blows over grammar. I had traditionalists on my right, modernisers on my left. The question in debate: is ‘data’ singular or plural?

This might seem like a small point, but it comes up a lot in business writing. Most senior staff argue it should be plural. Newer entrants to the business world never give it a second thought but instinctively choose singular.

So who’s right?

Why could data be plural?

‘Data’ was originally a Latin word. In Latin, it was plural. So if you wanted to refer to data (I’m not sure how often they referred to data in ancient Rome), you would use it in a plural form: ‘The data were collected over several years’.

The same applied for agenda, criteria, fora, media, memoranda – to name but a few.

These words became part of the English language, and everyone treated them the same way in English as they did in Latin. And so it remained for many years.

Why could data be singular?

However, English is an ever-changing language. Over the past few decades, there’s been a popular shift from treating data as plural to singular.

Writing authorities took a while to catch up, but most now agree you can treat data as both singular and plural.

The Oxford Dictionary of English holds this position:

‘Despite the complaints of traditionalists, it [data] is often not treated as a plural. Instead, it is treated as a mass noun, similar to a word like information, which cannot normally have a plural and which takes a singular verb. Sentences such as data was (as well as data were) collected over a number of years are now widely accepted in standard English.’

What about other Latin-origin words?

So data can be treated both ways. But has the tide turned for other Latin-origin words?
For some, yes; for others, no.


This has been treated as singular in English for a long time. You’d never say, ‘The agenda for Monday’s meeting were circulated yesterday’. In standard English, the plural of agenda is agendas.


Criteria is still plural. The singular form is criterion, which is rarely used.


Fora is the Latin plural for forum. It’s no longer common to use fora except when referring to the marketplaces of ancient Rome. Better to use forums as the plural.


This can go either way, depending on the context. Media is often treated as a mass noun, and it’s now equally correct to say ‘The media is/are hounding me’.


You can use memoranda or memorandums for the plural. The singular is memorandum.

In conclusion

This is not about right and wrong. Choosing between singular and plural in Latin-origin words is almost a political position. So pick a side and nail your colours to the mast. But whatever you choose, be prepared for battle.