"Is it an interesting book?"
Translation:¿Es un libro interesante?
This is hard to put into words... basically, that's not the reason to distinguish between ser and estar. The book being interesting is a more immutable quality of the book; if it was talking about whether the book was clean or dirty, you would use estar. But just because some people might say it's interesting and some might say it's uninteresting, they would both be describing a quality of the book (its interesting-ness, I suppose!) that is inherent and not temporary.
I put; "¿Es el libro interesante?", saying what I thought translated to, "Is the book interesting?". I honestly thought it would accept this. What I did not understand was why, if the word 'book' is the subject, would it correct me and say "un libro". To clarify, why is "¿Es un libro interesante? / Is a book interesting", correct?
I'd recommend reading through some of the other comments here, particularly the reply from EugeneTiffany--I think your question will be well answered. In short, this is a pretty pedantic distinction imo but it is helping to teach a couple important things.
Literally, "is a book interesting" is a correct translation, but that's not quite the meaning a fluent speaker would interpret it to mean. In Spanish there's an unspoken "it" that goes with "es," if there's not another subject identified. So it's more like, "It is an interesting book," or, because it's a question, "Is it an interesting book?"
This "silent subject" of 'it' in Spanish has an analogue in English through the way we say commands. "Go away" is a complete sentence, but if we look at its grammar word-for-word, it appears not to have a subject! But actually, the subject is unspoken, which we understand from context—someone might be saying "go away" to their parent, or a cat, or a meddlesome ghost. The way we understand this sentence, the subject could be written as "you"--"[You] go away." But we don't say it that way; that's just not the typical grammatical style of commands! The unspoken "it" that EugeneTiffany details is just one of those things that you have to get the hang of, it definitely doesn't translate in a smooth word-for-word way.
so I'm answering this way late and you've probably figured it out by now, but to me this reads more like a philosophical question. "Is a book interesting?" could be talking about the vague idea of a book; to ask this question, "Is [this specific book!] an interesting book?", you have to attach the adjective (interesante) unequivocally to the noun (libro). I don't know if that made sense but maybe it'll help somebody
I see a few problems with this. The gender matching is off--it should be "este," I think "esto" is only used when there's no specific noun. But also, "este" isn't quite the right meaning here; see a previous reply about the English word "it" from EugeneTiffany, but a more appropriate word is the plain article, "un," for AN interesting book.
Certainly! So first of all, you'll notice that there's only one letter different between your answer and the "correct" one; the second "e" in "Ese." If that's just a typo and you meant to say, "Es un libro interesante?" then you nailed it.
But "ese" has another meaning in Spanish. Literally translated, your answer says "That an interesting book?" Which is okay in some dialects of English, but it doesn't have a verb--to have a formally complete sentence, we need to say "IS that an interesting book," or "ES ese un libro interesante."
Finally, this is subtle (and a bit of a nit-pick if you ask me, but important for learning), but the word "that" is not the same as the word "it." See EugeneTiffany's reply previously for a thorough breakdown of translating the English word "it," but basically, by saying "ese," you're saying something slightly different than what the original sentences says. By simply saying "es," you imply the English "it is," or in this case, "is it?"