[21twelve]

I was just reading an article that made it sound like the terms data and datum have gotten a bit looser over the years. But yes - datum is a single point. Although I usually think of datum as the point used to base all of the other data off of (like a survey elevation datum).

That one article said that data is always plural. And then they gave numerous sentences as examples, including:

“The data from the experiment was inconclusive.”

With “was” being the singular form! I think it sounds better to the ear with “was” though. I don’t think it is that big of a deal.

[Verginius Rufus]

Datum is neuter singular (the perfect participle of dare, "to give"--something given), and data is the neuter plural form.

In Greek neuter plurals take a singular verb...so maybe the person who used "was" with "data" was just over-educated.