Learn Hardcore Spanish (Spain): Quiero encontrar un libro de poesía que no sea muy difícil. - I want to find a poetry book that is not very difficult.

Quiero encontrar un libro de poesía que no sea muy difícil.
→ You don’t have a specific book in mind; you’re just describing the kind of book you want.

Compare:

Quiero el libro de poesía que no es muy difícil.
→ You and the listener both know which book you mean. It’s specific, already identified, so you use indicative (es).

So:

un libro… que no sea… → any book that isn’t very difficult (subjunctive)
el libro… que no es… → that particular book that isn’t very difficult (indicative)

Could I say Quiero un libro de poesía que no es muy difícil? Is it wrong?

It’s not strictly “wrong”, but it changes the meaning:

Quiero un libro de poesía que no sea muy difícil.
→ I’m looking for some poetry book that isn’t very difficult (I don’t know if it exists yet).
Quiero un libro de poesía que no es muy difícil.
→ Sounds more like there is already a specific book known to both speakers and you want that one.

In real life, native speakers sometimes do use the indicative even with un, but the “textbook” and most natural neutral-Spanish choice here, when you are just describing the type of book you’re hoping to find, is que no sea muy difícil (subjunctive).

Why is it libro de poesía and not libro de poemas?

Both are possible, but there is a nuance:

un libro de poesía
- Very general: a poetry book, a book whose genre is poetry.
- Could be a collection of poems by one author, an anthology, or even a theoretical book about poetry.
un libro de poemas
- Focuses more clearly on it being a collection of poems.
- Sounds like “a book of poems”.

In most bookshop situations, libro de poesía is perfectly natural. If you specifically want a collection of individual poems, you can say un libro de poemas.

Why do we say de poesía and not an adjective like poético?

Spanish very often uses “noun + de + noun” instead of an adjective, especially for types of books, films, etc.:

un libro de cocina – a cookbook
una película de terror – a horror film
un libro de poesía – a poetry book

There is an adjective poético/poética, but:

un libro poético = a poetic book (the style or tone is poetic; it could even be prose)
un libro de poesía = a book whose content is poetry

So de poesía clearly describes the content/genre, which is what you want here.

Does poesía mean “poetry” or “poem”? How is it used?

Poesía can function in two main ways:

Uncountable / mass noun – “poetry” in general:
- Me gusta la poesía. – I like poetry.
- Quiero un libro de poesía. – I want a poetry book.
Countable – a single poem (more literary / less everyday):
- Escribió una poesía para su hija. – He wrote a poem for his daughter.

For learners, it’s useful to think:

la poesía = poetry (in general)
un poema = a poem (most common word)
una poesía = a poem (more literary)

In the sentence you gave, poesía is clearly the mass-noun sense: “poetry”.

Why is difícil the same for libro (masculine) and for cosa (feminine)? Shouldn’t it change?

Difícil is one of many adjectives in Spanish that end in -l, -e, -z, -ar, -ir, etc. and do not change for gender:

un libro difícil (masculine)
una tarea difícil (feminine)

They do change for number:

libros difíciles
tareas difíciles

So:
difícil / difíciles – same for masculine and feminine; only the plural changes.

Why is the no before sea? Could I say que sea no muy difícil?

The normal pattern in Spanish is:

no + verb + (muy) + adjective

So:

que no sea muy difícil = that is not very difficult

Putting no after the verb (que sea no muy difícil) sounds very unnatural and almost never appears in everyday speech. You might occasionally see something like no muy difícil as a phrase:

Quiero algo no muy difícil.

But when there’s a verb, the no usually goes directly before the verb:

no sea difícil
no es difícil
no quiero
no entiendo

Could I just say Quiero un libro de poesía que no sea muy difícil without encontrar? What’s the difference?

Yes, you can say both, but there’s a subtle difference:

Quiero un libro de poesía que no sea muy difícil.
- Literally: I want a poetry book that’s not very difficult.
- Focuses more on the desire to have/possess such a book.
Quiero encontrar un libro de poesía que no sea muy difícil.
- Literally: I want to find a poetry book that’s not very difficult.
- Emphasizes the action of finding / looking for the book.

In a bookshop, saying Quiero encontrar… sounds very natural because you’re explicitly talking about the act of searching. But Quiero un libro de poesía que no sea muy difícil would also be perfectly fine and natural in context.

Why is it un libro and not algún libro? What’s the difference?

Both are grammatically correct:

Quiero encontrar un libro de poesía que no sea muy difícil.
→ I want to find a poetry book that’s not very difficult. (Neutral, standard.)
Quiero encontrar algún libro de poesía que no sea muy difícil.
→ I want to find some poetry book that’s not very difficult. (Slight emphasis on “some (any) such book”.)

Algún adds a nuance of “some / any”, but in many contexts, un already carries that meaning, especially with the que + subjunctive structure. That’s why un libro de poesía que no sea muy difícil is the most typical version.

Where does the clause que no sea muy difícil have to go? Can I move it?

The relative clause que no sea muy difícil must come right after the noun it describes:

✅ Quiero encontrar un libro de poesía que no sea muy difícil.

If you move it away from libro, it sounds wrong or confusing:

❌ Quiero encontrar que no sea muy difícil un libro de poesía.

Spanish is quite strict about keeping relative clauses (the part starting with que) immediately after the noun they modify, especially in simple sentences like this.

Is this sentence specifically “Spanish from Spain”? Would a Latin American speaker say it differently?

The sentence:

Quiero encontrar un libro de poesía que no sea muy difícil.

is perfectly normal and natural both in Spain and in Latin America.

There is no regional difference here in vocabulary, grammar, or structure. A Mexican, Argentinian, Colombian, or Spanish person could all say this in exactly the same way.

Regional differences would show up more in other areas, e.g.:

ordenador (Spain) vs computadora (Latin America) for “computer”

But in this particular sentence, it’s standard everywhere.

How do you pronounce poesía and why does it have an accent?

Poesía is pronounced approximately:

[po-e-SI-a] (four syllables)

The accent mark tells you two things:

Where the stress goes:
- Stress is on -sí-: po-e-sí-a
That the vowels don’t form a diphthong:
Without the accent, oe or ía might be interpreted differently. The accent shows that the i is stressed and separate, creating po-e-sí-a instead of something like poe-sia.

In IPA, roughly: [po.eˈsi.a].