My guess is that you've seen kot and krab in sentences like "Kot to zwierzę" where you use zwierzę in nominative and ryba in a sentence "Ryba jest zwierzęciem" where zwierzęciem is just instrumental of zwierzę
Both zwierzę and zwierzęcie are synonymous. I just had a discussion about whether there is a slight subtle difference or not and it's really hard to tell. Apparently, as a rule of thumb, zwierzę is rather used when refering to bigger animals, while zwierzęcie can be use on any animal. It's probably mostly just a matter of taste.
Not exactly - there is no polish word 'zwierzęcie', but similiar forms appear in declension:
What perhaps confused You is that there is a second word for animal in Polish, which is 'zwierz' (which is masculine, while 'zwierzę' is neuter), but it is rarely used - mostly in fixed phrases or stilizations , as it is considered out-of-date.
I keep seeing people use zwierzęcie from time to time, though itseems that zwierzę is far more popular. Not sure whether zwierzęcie is completely false though. Maybe it just came into use because the other declinations resemble this form. Well, I guess only time (and some professioanl linguists) will tell whether it's completely wrong or just unusual.
You can use to only between two nouns, and być can by used practically always.
When to and być are used with nouns, are they interchangeable (other than that the instrumental case is used with być)?
No, they are not interchangable. Być is a verb, while to is not. To means just as much like that or that is, so it's quite difficult to translate the given sentence, as you have no verb in it. But it makes perfect sence in Polish and if you want classify something, then it's perfectly fine: Pies to ssak = The dog is a mammal. In all these cases to is always translated with is an... or is a...
kot jest jeden. Dlaczego jest v "correct" takze odpovidz "Cats are animals"? nie jest to bland?
Unless you specify ten kot or tamten kot in the polish sentence, it's perfectly fine to translate it as cats are animals because the polish sentence is a generalization. ten/tamten kot would just men this/that cat is an animal, implying that there are cats that are not animals.
zdanie jest tylko "Kot to zwierze". Z mego poglodu "ten kot" i "tamten kot" jest tylko jeden kot, wienc tlumaczyc tego jak lyczba mnoga jest blendem
Wręcz przeciwnie. Mówiąc kot to zwierze mówi się o kocie jako taxonomiczny okaz, obejmując wszyskie koty na świecie. Dopiero ten lub tamten kierunkuje znaczenie na jedno indywiduum.
On the contrary. Saying kot to zwierze you talk about the cat as a taxonomical species, comprising all individuals of the species. Only ten or tamten direct the meaning on one individual of the species.
You're welcome! Always feel free to ask me when you have any problems :) and by the way, it's dziękuję and wytłumaczenie.
Exactly. The correct vesion is to say kot jest zwieręciem. X jest ... always requires you to put the object in the instrumental case. Just a few examples: Golf jest samochodem (the Golf is a car), Kanarek jest ptakiem (the canary is a bird), jabłko jest owocem (the apple is a fruit).
Things look a bit different if what's following the jest isn't an object but a location description (mucha jest na zwierzęciu - the fly is on the animal), in which case we require the locative case.
If what's following the jest is an adjective, because you want to describe how someone/thing is, then the adjective is always in the nominative case: Jestem zmęczony (I'am tired).
There's also the option to use demonstrative pronouns (ten, ta, to = this; tamten, tamta, tamto = that): To jest moja żona (this is my wife). In this case, the object (moja żona) is in the nominative case. If you replace the demonstrative pronoun with a regular pronoun (on, ona, ono) then the object needs to be in the instrumental case again: Ona jest moją żoną (she is my wife).
I know this is very confusing and sadly I can't say more than that you will have to learn it all by heart. As you may have noticed, Polish has extremely complex grammar. Just don't let it discourage you!
The notes to this lesson have this example: "Tygrys to kot. (Literally: The tiger is a cat, in this case more like: Tigers are cats)"
But "cats are animals" is not accepted here - is there a difference I'm not seeing?
Well, on the one hand, they are totally different sentences, singular and plural. On the other hand, there is some logic to accepting it, as in meaning they are very close. If the T&N approved it explicitly... I guess we have to add "Cats are animals" here, then. Done.
If you know Russian, it's easier to define the case. If there is "jest, jestem, jesteś etc.," you must imply there Russian verb "являться" in necessary conjugation. And "являться" requires Instrumental(кем, чем) in Russian, so it gives you a hint that the same case must be used in Polish. And if there is "to", remember Russian "это", and in Russian in the same situation Nominative is to be used. Examples: (Ja) jestem mężczyzną. Я являюсь мужчиной. Tygrys jest zwierzeciem. Тигр является животным. Chłopiec to dziecko. Мальчик - это ребёнок. Lew to zwierze. Лев -это животное. Looks complicated, d there is direct correlation.