"Japan and China are countries in Asia."
Translation:Japanio kaj Ĉinio estas landoj en Azio.
Can China also be called "ĥinio"? One of my Esperanto books spells it that way and the ĥ sound is the normal way to pronounce the "ch" in "China" in German.
Ĥinujo might be more apt, since the root ĥin- is apparently pretty outdated (it's marked "ark." in the PIV dictionary) and so was probably seen more with the -uj- suffix that was originally used for countries.
Ĥinio can't be described as wrong, though, just unusual.
Why is it "landoj" and not "landojn?" The case is plural nominative so the ending should be "--jn"
Yes, exactly, plural nominative -- so the ending should be "-j".
-n is the marker of the accusative case so you would see -jn in the plural accusative.
I don't speak Vietnamese myself, but I tried to listen to the Vietnamese pronunciation of the name of the country [linked from the English Wikipedia; very low sound] page, and it seems to be closer to "vjet-" than "viet-" (i.e. not "vi-et-").
Not all countries have an Esperanto name "close to the country's pronunciation", but some have.
In this case I suspect it's more due to a "one syllable, instead of two" reason, though.
Because a japano is a Japanese person.
The country he inhabits is Japanujo or Japanio.
This is one of the many countries where the country name is formed from the name for the inhabitants and so the country name has an ending -uj- or -i-.