Nan = what

Kore - This (something close to the speaker physically/emotionally)
Sore - That (something close to the listener)
Are - That (something distant from both speaker and listener)

Jin = person
Amerika-jin = America person = American
Nihon-jin = Japan person = Japanese
Doitsu-jin, Igirisu-jin, Supein-jin, Furansu-jin

DESU vs DES

The "u" at the end of verbs is barely pronounced or dropped altoether.
It's pronounced more clearly when the speaker is being extra-polite.

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