Well, Portugal is not quite remember by most of people. It's not like Germany or France, from which we get lots of political news every week. Talking as a Brazilian, I guess Portugal seems more like a forgotten memory from History school books to most of Brazilians (and I say that because I made some friends/relatives take the Countries of the World quiz and Portugal was not an easy one for them to remember).
Probably people not speaking the language still trying the quiz. 'United Kingdom' is completely different in every language (Vereinigtes Königreich, Royaumi Uni, etc) and difficult to guess. While eg 'Canada' is virtually the same in every language and easy to guess.
And because "The UK" is not nearly as ubiquitous as "USA". For example, the German language version will give you USA as a type-in, but requires VK rather than UK, despite the U translating from and to the exact same word (United -> Vereinigte/s, as pointed out).
Meanwhile, out of this particular language set, 8 quizzes would accept Canada and the other 7 would accept Kanada.
Probably because most people who took the Vietnamese CotW aren't actual Vietnamese speakers. CUBA is accepted so you would be able to get it without any knowledge of the language.
Meanwhile, out of this particular language set, 8 quizzes would accept Canada and the other 7 would accept Kanada.
So take my +1/
FML
WALES IS IN THE UK!!!!!!1!1
Try this: https://www.jetpunk.com/user-quizzes/1744710/most-guessed-countries-in-each-languages