"I went to South Korea on the weekend."
I really wish that the Japanese sentence would be read aloud in the puzzle exercises,so I could practice the readings of the kanji! At least the default answer or maybe just the individual words.
朝鮮 (朝鮮民主主義共和國) is Korea (Democratic People's Republic of Korea) and 韓國 (大韓民國) is Korea ([Great] Republic of Korea)
These are also Hanja characters, which is same as TraditionalChinese characters and Kyujitai Japanese characters.
Why is not South Korea the subject? "On the weekend" I had never imagined to be the object
You're right confused!
There's no "subject" here. A subject is an agent that does an action, and the object has that action done to them. So, I (the subject) go (the verb/action) to South Korea (the object). In Japanese a subject is marked with が, but there's no agent mentioned here, only implied. So there's no が and no subject.
Instead the TOPIC is marked with は. In this case the topic is the weekend. The topic is basically the main point of the sentence, like sort of the reason why the sentence is being spoken. In this case, the important point is that this takes place at the weekend - so the weekend is marked as the topic.
I hope that makes sense.
I got caught out on two counts here:
Because the term for "South Korea" has previously been used to refer to "Korean" things in general, I was looking for the word "South" to add in, which isn't needed;
I keep forgetting that when referring to the weekend, you need a particle. As I recall you don't need this for words such as 昨日 (yesterday) or 今朝 (this morning). How come?