Learn Hardcore Spanish (Spain): Este libro sobre política no es aburrido; en realidad me gusta mucho y realmente me hace pensar. - This book about politics is not boring; in fact I like it a lot and it really makes me think.

este / esta / estos / estas → this / these (near the speaker)
ese / esa / esos / esas → that / those (near the listener or a bit farther away)
aquel / aquella / aquellos / aquellas → that / those over there (far from both)

Este libro suggests the book is close to the speaker (physically or in the current conversation: e.g. the book in my hands, on my desk, or the one we just mentioned).
You could say ese libro or aquel libro if you want to show more distance, but that would slightly change the nuance. The sentence is perfectly natural with este to mean this book.

Why is it sobre política and not de política?

Both sobre política and de política can mean about politics, and both are correct.

sobre often emphasizes topic/subject:
- un libro sobre política = a book on politics
- una charla sobre música = a talk on music
de is more general, used for many relationships (possession, origin, content, topic, etc.):
- un libro de política can also mean a politics book / a book about politics.

Here, sobre is very common and maybe a bit more precise for “on the subject of politics,” but de política would also be fine.

Why is política feminine here? What exactly does política mean?

Política with -a and the article la is a feminine noun:

la política = politics (the activity, the field)
las políticas = policies (government measures)

Related words:

el político = male politician
la política (person) = female politician

In libro sobre política, política is a noun meaning politics as a field of study or topic. It is feminine by convention; many abstract nouns ending in -ica or -ía are feminine (la música, la economía, la filosofía, la historia).

Why do we say no es aburrido and not no está aburrido?

This is the classic ser vs. estar difference:

ser aburrido = to be boring (in general, as a characteristic)
estar aburrido = to be bored (temporary state of a person) or occasionally to be boring right now in a specific context.

Here, el libro no es aburrido means the book is not boring as a quality of the book.
If you said el libro no está aburrido, it would sound odd; we normally don’t use estar aburrido for objects in this way. For a person, you’d say:

No estoy aburrido. = I’m not bored.

Why is it me gusta mucho instead of yo gusto mucho el libro?

The verb gustar works differently from English to like:

The thing that pleases is the subject.
The person who likes is an indirect object with me / te / le / nos / os / les.

So:

Me gusta este libro.
Literal idea: This book pleases me.
Meaning: I like this book.

Structure:

me = to me
gusta = pleases (3rd person singular)
este libro = subject

Saying yo gusto el libro is incorrect for “I like the book.”
Gustar almost always uses this special structure.

Why is it me gusta mucho and not me gusta muy?

Muy and mucho are different:

muy modifies adjectives and adverbs:
- muy interesante = very interesting
- habla muy rápido = he/she speaks very fast
mucho modifies verbs or nouns:
- trabaja mucho = he/she works a lot
- me gusta mucho = I like it a lot / very much
- mucho dinero = a lot of money

Since gusta is a verb form, you use mucho:
Me gusta mucho = I like it a lot or I really like it.

What is the difference between en realidad and realmente? They both look like “really.”

They are related but not identical:

en realidad = actually / in fact
It often introduces a contrast or clarification.
- Pensaba que era aburrido; en realidad es muy interesante.
realmente = really / truly / genuinely (adverb modifying a verb, adjective, or whole clause)
- realmente me gusta = I really like it.
- es realmente bueno = it is really good.

So in the sentence:

en realidad = actually / in fact (contrasts with the idea that the book might be boring)
realmente = really / genuinely (intensifies me hace pensar).

Isn’t using both en realidad and realmente repetitive? Would a Spaniard actually say that?

It is a bit emphatic, but it’s natural and something you can hear in Spain. The two parts add different nuances:

en realidad me gusta mucho → in fact I like it a lot (contrast with expectations)
y realmente me hace pensar → and it really makes me think (intensifies the effect it has on you)

You could shorten it:

Este libro sobre política no es aburrido; me gusta mucho y me hace pensar.
Este libro sobre política no es aburrido; de hecho me gusta mucho y me hace pensar.

But the original with both en realidad and realmente is grammatically correct and stylistically fine.

How does realmente me hace pensar work grammatically? Why is me before hace?

The structure is hacer + infinitive to express “to make someone do something”:

hacer pensar = to make (someone) think
me hace pensar = it makes me think
te hace reír = it makes you laugh

Word order:

Object pronouns (like me, te, le, nos, os, les) usually go before a conjugated verb:
- me hace pensar
- te hace reír

So the pattern is:

[subject] hace [pronoun] [infinitive]
→ Este libro (subject) me hace (verb + pronoun) pensar (infinitive).

Why is there a semicolon ( ; ) between aburrido and en realidad?

The semicolon in Spanish works similarly to English:

It links two closely related but independent clauses that could be separate sentences.

Here:

Este libro sobre política no es aburrido
en realidad me gusta mucho y realmente me hace pensar

They could be written as two sentences, but the semicolon shows they are tightly connected.
A comma would be less correct here because each side has its own verb and subject structure.
You could also write:

Este libro sobre política no es aburrido. En realidad me gusta mucho y realmente me hace pensar.

Where can mucho and realmente go? Can I move them around?

There is some flexibility, but not every position sounds equally natural.

For mucho with gustar:

Very natural: Me gusta mucho.
Also possible: Mucho me gusta este libro. (more literary/emphatic, less common in everyday speech)
Avoid: Me mucho gusta (incorrect).

For realmente:

Realmente me hace pensar. (neutral)
Me hace realmente pensar. (slightly more emphasis on really makes; still okay)
Me hace pensar realmente. (often understood as it makes me think, really; also fine)

So the original me gusta mucho and realmente me hace pensar are the most natural, neutral positions.

Why is aburrido masculine and singular? Would it change with a different noun?

Adjectives in Spanish agree with the noun in gender and number.

libro is masculine singular ( el libro ), so:
- libro aburrido = boring book
- no es aburrido = it (the book) is not boring.

If the noun changed, the adjective would change too:

la película no es aburrida (feminine singular)
estos libros no son aburridos (masculine plural)
estas series no son aburridas (feminine plural)

So aburrido matches libro: masculine, singular.