The English sentence here with "popular" is a mistranslation of the Portuguese "popular," which, in this case, means "of the people" and not "well-liked."

I'm new to this site and not sure about its workings. Which one is the root sentence? I thought I translated an English term; was this in fact an English translation of a Portuguese sentence? If I did anything wrong, how do I go about to correct it?

No problem, here is roughly how it works

there's no "absolute" root sentences, each time when you translate, you're actually translating the top sentences, but if you mean to translate one the sentence below, then you need to change the "root" sentence, simply by clicking on the sentences you want to translate :)

When you get it wrong, advanced user can fix link between translation, so you just drop a comment explaining what is to link/unlink and it should be fine

welcome to tatoeba by the way, we used to have not so many Swedish speakers, so I'm really glad to see you there :)

Thanks for the explanation and the warm welcome. The concept of this site really appeals to me, and I'll try to keep contributing. Doing a few sentences every now and then is actually a pretty nice pastime! :-)