"A horse is an animal."
Translation:Koń to zwierzę.
No, there are no such rules, although we consider too clumsy to say "On to mój tata", so for "He is my dad" that should be "On jest moim tatą". So in this way "to" is used less with people, I guess.
Using "to jest" ("Koń to jest zwierzę") is possible, but relatively rare, we don't teach it, we just accept it.
https://www.duolingo.com/comment/16373167 - you may check if this article helps you.
Koń jest zwierzęciem should (as zwierzęciem is the instrumental form of zwierzę, neuter, most of the -ę nouns decline with additional -t-/-ci- in the root).
Zwierzem also exists, and is instrumental of zwierz (masculine), which can also mean animal, but sounds odd and wouldn’t be used in normal speech (Wiktionary suggests it is poetical and figurative)
It should be zwierzęciem. I think this course would just accept everything without Polish diacritics – but that is wrong. You should probably report it.
And ę here is pronounced differently than in zwierzę. It would be something like [zvʲɛˈʐɛ̃ɲt͡ɕɛm] – as if it was written *zwierzeńciem – because the /ć/ sound that appears after /ę/ is soft (palatal), the /ę/ is realised as /eń/.
Before /t/, /d/, /s/, /z/ (some dental, and hard, ie. non-palatal, consonants) it would be pronounced as /en/.
Before /b/ and /p/ (bilabial consonants) it would be /em/.
And so forth – /ę/ is pronounced always as nasalised /e/ followed by a nasal consonant with the same place of articulation as the next consonant. And just as /e/ if it is at the end of a word.
No. Both koń to zwierzę and koń jest zwierzęciem mean exactly the same, and without context would be understood as ‘a horse is an animal’ (but in some contexts both could mean that ‘the horse is the animal’).
Using być (the ‘to be’ verb) + instrumental is just one way for making copular (defining) sentences in Polish (and some other Slavic languages, like Czech).
Why instrumental is actually used here, and not some other case? For the answer we would probably have to ask some Proto-Slavs or even Proto-Balto-Slavs, from over thousand (or more) years ago, as they started to use that construction.
it's emotionally wrong. While technically "zwierzak" is augmentative, it works more like diminutive/endearment.
wsjp. pl = zwierzę, w stosunku do którego mówiący odczuwa sympatię lub współczucie / animal that speaker likes or feels symphaty/compassion
sjp.pwn; wikitionary -zwierzak= tenderly "zwierzę"
-em/-iem is a masculine/neuter Instrumental ending. Instrumental is mostly used after the word "z" = "with", when something is used 'as an instrument', and a sentence like this one.
Read more about it here: https://mowicpopolsku.com/polish-grammar/cases/instrumental/