Translation:Where are we going to go on Wednesday?
Well, this gets into the argument of descriptive grammar versus prescriptive grammar. In the English-speaking world, no authority claims to prescribe usage (there's no equivalent of the Real Academia Española), so really, dictionaries only describe how people use English. "To where" has fallen out of usage, so it can reasonably be described as outdated or incorrect, where as "Where are"... is commonly used and commonly understood, which descriptively makes it correct.
That's an interesting perspective. I've only ever seen the prescriptive/descriptive argument for including 'nonstandard' usage, not for excluding uncommon or archaic usage. I guess i kind of like seeing old fashioned style, aesthetically. As long as it doesn't actually cause conflict or confusion with more modern usage, I don't see any reason to exclude it. Anyway, you've given me something to think about.
Colloquially, Where are we going to Wednesday? "going to" being a phrase separate from Wednesday. I would have written "To where are we going Wednesday?" but figured DL would mark it wrong. I wish DL would make a definitive decision if they want to accept proper grammar, normal usage or both (my preference).
This is a good question as it covers three variations that are possible in translating this sentence: The commonly dropped preposition "on"; the possible repositioning of the preposition "to"; and the pseudo future tense formed by reference to a future time frame coupled with a present participle ("going" vs "going to go"). There is also the optional "to" after "go." These four variations give us sixteen permutations:
Four that match tense and are common:
Where are we going to go Wednesday?
Where are we going to go on Wednesday?
Where are we going to go to Wednesday?
Where are we going to go to on Wednesday?
Four that don't match tense but are common:
Where are we going Wednesday?
Where are we going to Wednesday?
Where are we going on Wednesday?
Where are we going to on Wednesday?
Two that match tense but aren't common:
To where are we going to go Wednesday?
To where are we going to go on Wednesday?
And two that don't match tense and aren't common:
To where are we going Wednesday?
To where are we going on Wednesday?
Arguably all of the above could be included in the answer database. The only definite exclusions should be the following, in which the doubling of the preposition "to" is incorrect:
To where are we going to Wednesday?
To where are we going to on Wednesday?
To where are we going to go to Wednesday?
To where are we going to go to on Wednesday?
Yep, there is actually a grammatical difference between "will" and "going to" but very few people know this and even less care. Spanish speakers hold exactly the same view, so pretty much either version should be acceptable in either language. After enough reports DL will undoubtedly accept this too.