Translation:At the restaurant, the children's mothers and fathers are sitting.
If you said the translated version in America people would understand you, but it would sound Very odd. "The children's mothers and fathers are sitting in the restaurant." makes much more sense. Being lazy we'd even more likely say, "The kids' parents are in the restaurant.", but that's not the best way to learn the Swedish words for mothers and fathers. :-)
Yes, it's really awkward in English and not natural at all to have the parts of the sentence in that order. But, it' Swedish that I'm learning so I'll go along with it. I have two questions: 1 - is this normal, in Swedish, to start the sentence/thought with the location? 2 - how would you invert this sentence to make a question? Tack!
To be fair, Barnens mammor och pappor sitter på restaurangen would be the most natural construction in Swedish as well. But you may encounter this construction as well. I'd say it sounds the most natural in certain contexts, like a narrative - in which case it works for English as well.
As for making it a question, I'd go with Sitter barnens mammor och pappor på restaurangen?
We accept both of those options and many others as well. But like I wrote above, this is one of those sentence where the default needs to be unidiomatic for the sake of the reverse translation option.
The default is perfectly grammatical if you add a comma, though. "At the restaurant, ... are sitting". I'll see to that it's added.
It's mostly due to the structure of the English sentence. While it is more usual to say "the children's parents are sitting at the restaurant", you could just as well say "at the restaurant, the children's parents are sitting" just for emphasis. It works for the Swedish sentence the same way, so you could as well say "barnens mädrar och fäder sittar på restaurangen." Hope this helps!
I've tried "At the restaurant the mothers and fathers of the children are sitting" and it's not accepted. Neither was "The fathers and mothers of the children sit in the restaurant". Can't see why, it seems to me the sentence' construction has been made unnecessarily complicated for the sole reason of teaching us a Swedish sentence.