Quick English grammar question

I have just received comments from a reviewer on a document I wrote. One sentence asks " Before starting this survey, did you know that there were three web sites containing different XXX data?" The reviewer changed “were” to “are” because the sites still exist. But we are asking them whether they knew about the sites in the past. My position is that “were” is past tense, and is therefore correct.

I’m right, aren’t I?

You aren’t wrong grammatically, but I think the question needs clarifying. Maybe something like “At the time you took this survey, were you aware of the three websites containing…”.

I agree with Hatchie. I can see two different ways of parsing the sentence, each of which makes use of implicit additional info (but not the same implicit additional info):

a) “[I have a question that I want to ask you] before starting this survey [:] Did you know that there…”

b) “[At the time prior to when you started this survey, i.e.,] before starting this survey, did you know that there…”

Yes.

(some more characters, since all posts now require at least 5)

This is one of the instances where you can tell that, for a long time, English grammarians tried to emulate Latin grammar. Latin has strict rules about the sequence of tenses (consecutio temporum) which would require, in that sentence, the past tense. The logic is that the action in the subordinate clause takes place at the same time as the action in the main clause and therefore needs to follow the same tense, in this case the past tense. These principles were transposed by English grammarians of the past into English, but nowadays they are followed less strictly.

Does it bother any of you that the question had the phrase “did you know”, when it could have (should have?) had the phrase “do you know”?

I disagree. “Before starting this survey” is asking for knowledge in the past. “Did you known then” vs. “now that you do know, even if you hadn’t before.”

I’ve gone back and forth on the question of “were” vs “are” because of the current existence of the websites. (I write websites as one word; I’m surprised no one else has commented on that.) I’ve landed on the side of “were.” The question as phrased asks for prior knowledge. That should be expressed with the past tense.

Without knowing this, my gut said “were” was correct, and this seems to back me up.

And as a practical matter, if you began your survey in, say, October of 2019, there would be no way you could have known that there are three websites in July of 2020. You might have known that there were three websites in October.

I’m not a grammarian, but I think the sentence in the OP is clear, correct, and unambiguous.

I’m not so sure of that. I have no idea what XXX data is.

Pornhub provides plenty of it in its annual report.