Is 'data' singular or plural?

In English, the word data can be treated as singular or plural, depending on the context. That’s why many writers get confused.

Everyday use: singular

In most everyday and modern writing, data is treated as an uncountable word, like information or evidence. It means a body of information, not separate pieces.

• This data shows how students perform over time.
• The data is accurate and complete.
• Her data was lost after the system crash.

Here, “data” takes a singular verb, and we use this and it.

Scientific or formal use: plural

In technical or academic writing, especially in science or statistics, data is treated as the plural of “datum” (one piece of information), with plural verbs.

• These data are statistically significant.
• We analyzed the data and found that they were consistent with the hypothesis.
• Most of these data were collected in 2020.

Here, we use these and they. Whichever you choose, stay consistent. And never add an -s:

• ❌ We collected a lot of datas.
• ✅ We collected a lot of data.