Learn Hardcore Spanish (Spain): Este poema tiene un ritmo sencillo y un vocabulario que entiendo bien. - This poem has a simple rhythm and vocabulary that I understand well.

Most Spanish nouns ending in -a are feminine, but there is an important group of exceptions: many words of Greek origin ending in -ma are masculine.

Examples:

el poema (the poem)
el problema (the problem)
el tema (the theme, topic)
el sistema (the system)
el programa (the program)

Because poema is masculine, all the words that agree with it must also be masculine:

este poema
un poema
el poema

So esta poema is grammatically incorrect; it must be este poema.

What’s the difference between poema and poesía?

They are related but not the same:

poema = a poem, a specific text.
- Este poema tiene un ritmo sencillo.
  This poem has a simple rhythm.
poesía = poetry in general, or sometimes a poem viewed as poetry/art.
- Me gusta la poesía. – I like poetry.
- Esta poesía es muy emotiva. – Can mean This poem/this piece of poetry is very emotional.

Grammatically:

poema is masculine → el poema, este poema
poesía is feminine → la poesía, esta poesía

You cannot say este poesía; it must be esta poesía.

Why do we use este here? Could it also be ese poema or aquel poema?

Este / ese / aquel all mean “this/that”, but they show different degrees of distance (physical, mental or in time):

este poema – this poem (close to the speaker in some way)
- physically near, or
- just mentioned, or
- the one I have in front of me / I’m about to read.
ese poema – that poem (a bit more distant)
- maybe in front of the listener, or
- mentioned earlier but not the main focus.
aquel poema – that poem over there / that poem (way back then)
- physically far, or
- something from the distant past or more remote in the conversation.

In your sentence, este poema suggests the speaker is focusing on a particular poem that is “close” in context (e.g. the one we’re reading right now). Ese poema or aquel poema would also be grammatically correct but would change the nuance of distance.

Why is it tiene un ritmo sencillo and not something like hay un ritmo sencillo or es de ritmo sencillo?

Spanish often uses tener + noun to describe characteristics of something:

tener un ritmo – to have a rhythm
tener un color – to have a color
tener una forma – to have a shape
tener un sabor – to have a taste

So:

Este poema tiene un ritmo sencillo.
This poem has a simple rhythm.
→ The rhythm is a feature of the poem.

Alternatives:

Hay un ritmo sencillo en este poema.
There is a simple rhythm in this poem.
→ Grammatically correct, but it sounds less natural and a bit heavier; it shifts the focus away from “the poem” as subject.
Este poema es de ritmo sencillo.
This poem is of simple rhythm.
→ Possible, but more formal/literary; in everyday speech tener un ritmo sencillo is more idiomatic.

What exactly does ritmo sencillo mean? Is it “simple rhythm” or “easy rhythm”? And why is the adjective after the noun?

Meaning of sencillo:
- sencillo here means “simple, not complex, straightforward.”
- ritmo sencillo suggests the rhythm is:
  - regular,
  - not very complex,
  - easy to follow.
It’s closer to “simple rhythm” than to “easy rhythm” in the sense of difficulty of a task.
Adjective position: why ritmo sencillo, not sencillo ritmo?
- The default order in Spanish is noun + adjective:
  - ritmo sencillo
  - poema largo
  - vocabulario difícil
- Putting the adjective before the noun usually adds a subjective, emotional or stylistic nuance:
  - un sencillo ritmo would sound more poetic or expressive and is less common in neutral speech.

So un ritmo sencillo is the standard, neutral order: first the thing (ritmo), then the description (sencillo).

In English we usually don’t say “a vocabulary” about a poem. Why does Spanish say un vocabulario here?

In English, “vocabulary” is often uncountable (like water, information), but in Spanish vocabulario is very commonly used as a countable noun when talking about a set of words someone uses or understands:

tener un vocabulario amplio – to have a wide vocabulary
un vocabulario muy técnico – a very technical vocabulary
un vocabulario limitado – a limited vocabulary

So:

un vocabulario que entiendo bien literally = a vocabulary that I understand well,
but natural English would be:
the vocabulary is easy for me / it uses words I understand well.

It’s normal and idiomatic in Spanish to say un vocabulario in this context.

What is the function of que in un vocabulario que entiendo bien?

Here que is a relative pronoun meaning “that / which”. It introduces a relative clause that describes vocabulario:

un vocabulario → the noun
que entiendo bien → relative clause, “(that) I understand well”

So the structure is:

un vocabulario [que entiendo bien]
a vocabulary [that I understand well]

In English we can often omit “that”:

a vocabulary (that) I understand well

In Spanish you must use que here; you cannot drop it.

Why is it entiendo and not entienda after que? Doesn’t que often trigger the subjunctive?

The word que itself does not automatically cause the subjunctive. It depends on the overall meaning of the sentence.

Here:

un vocabulario que entiendo bien
describes a real, specific, known vocabulary.
The speaker is stating a fact: “I (actually) understand this vocabulary well.”
→ So we use the indicative: entiendo.

We use the subjunctive in a relative clause when the antecedent is unknown, hypothetical or not yet identified. For example:

Quiero un vocabulario que entienda bien.
I want a vocabulary that I (will be able to) understand well.
→ I don’t know yet which vocabulary; I’m looking for one.
→ entienda (subjunctive) is used.

In your original sentence, the poem and its vocabulary are already known and real to the speaker, so entiendo (indicative) is correct.

Why can Spanish drop the subject yo in que entiendo bien? Would que yo entiendo bien also be correct?

Spanish is a “null subject” language: you normally omit subject pronouns (yo, tú, él, etc.) because the verb ending already shows the subject:

entiendo → clearly 1st person singular → yo

So:

que entiendo bien = que yo entiendo bien, but without repeating “yo”.

que yo entiendo bien is also grammatically correct, but it adds:

emphasis or contrast, like:
- “that I understand well (as opposed to someone else)”
- or a more marked, emphatic tone.

In neutral speech, que entiendo bien is more natural.

Should there be a lo in que entiendo bien? Why not un vocabulario que lo entiendo bien?

No, there should not be a lo there.

In un vocabulario que entiendo bien:

que already functions as the direct object of entiendo:
- I understand what? → que (referring back to vocabulario).

If you added lo, you would be doubling the direct object:

un vocabulario que lo entiendo bien ✗ (incorrect in standard Spanish)

Acceptable alternatives:

Lo entiendo bien. – I understand it well. (when “it” has already been mentioned)
Este vocabulario lo entiendo bien. – Here lo doubles but the fronted phrase Este vocabulario is a topic; this kind of doubling is possible.

But with a relative clause, you must not add lo because que already does that job.

Can I change the word order and say que bien entiendo instead of que entiendo bien?

In this sentence, que entiendo bien is the natural word order:

verb (entiendo) + adverb (bien).

bien entiendo is:

possible only in certain marked or literary uses, often to emphasize “bien”:
- Bien entiendo que estás cansado. – I do understand that you’re tired.

But in your structure “un vocabulario que…”, saying:

un vocabulario que bien entiendo
sounds unusual and not natural in modern standard Spanish.

So you should keep:

un vocabulario que entiendo bien.

Is there any difference between entiendo bien and comprendo bien here?

Both entender and comprender often translate as “to understand”, and in this sentence they can be used almost interchangeably:

…y un vocabulario que entiendo bien.
…y un vocabulario que comprendo bien.

Nuances (especially in Spain):

entender is the more everyday, common verb.
comprender can sound a bit more formal or slightly deeper (to grasp fully), but this difference is subtle and often ignored in practice.

In everyday speech in Spain, entiendo is more usual, and that’s why the original sentence uses entiendo. Both are correct.

Could I say un ritmo simple or un ritmo fácil instead of un ritmo sencillo? Is sencillo especially “Spain Spanish”?

sencillo vs simple vs fácil
- sencillo and simple are very close in meaning here:
  - un ritmo sencillo / un ritmo simple → a simple, not complex rhythm.
- fácil tends to mean “easy for someone”, not just “simple in structure”:
  - un ritmo fácil sounds like “a rhythm that is easy (for people) to follow or perform”.
Usage in Spain:
- sencillo is very common in Spain, but it is also widely used in Latin America.
- simple is also common everywhere, though in some contexts it can carry a slight nuance of “plain / not fancy / even a bit negative”.
- In this neutral, descriptive context, ritmo sencillo is very natural and slightly softer than ritmo simple.

All three are understandable, but:

ritmo sencillo = safest, neutral choice for “simple, straightforward rhythm”.