Translation:We hebben elkaar gisteren ontmoet.
No. I wish I could explain the grammatical rule, but it just feels wrong as a native speaker and I don't know the rule...
I put elkaar and gisteren the wrong way round, compared to the above, but the correct answer was given as 'Gister hebben wij elkaar ontmoet' Could someone explain this construction, and why the above translation wasn't given in response to my error?
The two formulations work based on what you want to put emphasis on. That order puts emphasis on the fact that it happened yesterday. The above translation feels more neutral, while you could emphasize "we" (a specific person or people as opposed to other people you might have met) by using "wij" instead.