To express the idea of speaking some language, or something being written in that language, Russian has adverbs literally meaning "Russian-ly", "English-ly" etc.. :
They are formed from -ский adjectives by attaching по- and changing the tail to bare -ски: по-ру́сски, по-италья́нски, по-япо́нски, по-вьетна́мски, по-америка́нски, по-францу́зски and so on.
And remember, these words actually mean something done "in a certain way", so «суши по-американски» (American-style sushi) should not surprise you!
A relatively small group of short masculine nouns have an accented -у ending with в/на in the meaning of place (and only then):
Our course has about a dozen of them (there are about 100 in the language). Also, there exists a very small group of feminine nouns, all "-ь"-ending, that have a stressed Locative-2 ending:
All these nouns use their normal Prepositional form with "о" and "при".
This word is used with qualities that manifest "totally"— usually with negatives:
It comes from «ме́жду» + «наро́ды», i.e. "between"+"peoples", which is quite literally "international".
The loanword «интернациональный» means the same but has quite limited use in certain combinations like "international team" or "international debt" (mostly these are from political contexts). This course largely avoids this word.
Probably, "international team/orchestra" etc. is the context where you must use «интернациональный»).
The word for an "animal" is a nominalised neuter adjective, and its case forms follow adjectival pattern. Of course, its gender is fixed: