"I want a dog; I already have a cat."
Translation:Я хочу собаку, кошка у меня уже есть.
"есть" is a statement of existence. Which is an obligatory meaning in this particular sentence. Sometimes it depends on context, sometimes even forbidden:
- No «есть» when describing properties of your body parts (unless you have a few body parts that are not commonly found in humans). Eg, «У меня большой нос»(I have a large nose)
- No «есть» with illnesses / feeling unwell (У меня температура)
- When describing properties of something with adjectives, there is no «есть». Basically, if "I have a good X" = "My X is good", you do not need to specify its existence
With pets it is a hard choice because formally we must allow both interpretations sometimes:
- I have a cat (you may have thought I have no pets) = У меня кошка.
- "I have a cat" (in case you thought I have a dog or a turtle) = У меня кошка/кот.
- "I have a cat" (so that's why I bought cat food) = У меня кошка/кот. or, maybe "У меня есть кошка/кот"
Of course, these DO NOT mean the same. It is just that in English they are no different in the lack of any context.
Well, "есть" is a form of "быть" (to be), the only in use now. Its analogous to "is", which replaced all other forms. High brow academics (or wannabes) will also use "суть" (3rd person plural) when making profound statements (after all, "суть" is the word that means "essense")... usually incorrectly, but that is it.
Shady, you should collect up all the notes you have provided us on Duo into a book and sell it on Amazon. I would absolutely buy it to have all this great info in one place and you'd get some compensation for all the time and effort you've spent helping us out. Maybe collaborate with Zirkel and Olga!
This explanation is leaving me confused as to why this particular sentence does require есть after all.
Doesn't it exactly match all three "I have a cat." examples (existence of a pet that is, of all possible pet species, a dog, and the reason why the speaker wants a cat) and therefore, shouldn't require есть?
Not a native speaker, but from what I've learned so far, you can move уже and it would still be correct. However, I think Duolingo is teaching a specific word order that is most common in daily conversation, and adverbs like уже go before the verb that they modify in the word order Duolingo teaches.