With regards of Earth (which has lots of different attributes spread across its surface), it has been divided in two ways:
Which brings us the 4 Hemispheres of Earth.
North Tarawa - 7000 people
South Tarawa - 56000 people
So you can't really say Tarawa is the capital as it's not a city.
Kiribati is accepted for the language, idk if this is a new thing.