Exactly, other languages would use something like "Det är bara människan som utvecklat tal" or "Es ist nur der Mensch, der die Sprache entwickelt hat" depending on language
They identified nouns and adjectives in prairie dog communication, that also seems to vary with regional dialects. I'll try to remember to dig up a source when I'm not out and about later.
Edit: here's a not fully scientific link, but has names and links for people who want to go deeper in the science while being a decent lay person's overview.
Weren't science communicators talking about parts of speech in whale communication last year, too? They're using AI to identify patterns and variations in speech.
A rattlesnake can certainly communicate using sound, but is that language? Bright colors can communicate ideas of "do not eat this" across species as well, but they wouldn't fit my mental model of a language.
what is language than making sounds to convey meaning and then decoding said sounds to understand their meaning
human language is incredibly complex but a bee just buzzing a particular buzz that means "bear nearby" counts as a valid form of linguistic communication imo