Learn Hardcore Spanish (Spain): Ella prefiere mantener su vida privada fuera de las redes sociales. - She prefers to keep her private life off social networks.

Yes, you can drop Ella. In Spanish, the subject pronoun is often omitted because the verb ending (prefiere) already shows the person (3rd person singular: he/she/you formal).

Ella prefiere... = She prefers…
Él prefiere... = He prefers…
Usted prefiere... = You (formal) prefer…

Context usually makes it clear who you mean. You keep Ella when you want to emphasize she (for contrast or clarity).

Why is it prefiere and not preferir or prefiera?

preferir is the infinitive: to prefer.
prefiere is the present indicative, 3rd person singular: she prefers.
prefiera is usually a present subjunctive form (or formal command): that she may prefer / (you) prefer!

Here we’re simply stating a fact about her habit, so we use the present indicative:

Ella prefiere... = She prefers… (statement of fact or habit)

Why is mantener in the infinitive? Could it be mantiene?

In Spanish, after verbs like preferir, querer, poder, etc., you normally use an infinitive:

Ella prefiere mantener... = She prefers to keep...

If you said Ella prefiere mantiene, it would be wrong, because Spanish doesn’t use a double conjugation there. It’s conjugated verb + infinitive, not conjugated verb + conjugated verb.

What is the structure preferir + infinitive exactly?

The pattern is:

[subject] + preferir (conjugated) + [infinitive]

Examples:

Prefiero leer. = I prefer to read.
Ellos prefieren salir temprano. = They prefer to go out early.
Ella prefiere mantener su vida privada... = She prefers to keep her private life...

This is very common and works much like “prefer to + verb” in English.

Does su here mean her, his, their, or your? How do I know?

Su is ambiguous on its own. It can mean:

his
her
their
your (formal, singular or plural in Spain: usted / ustedes)

In this sentence, context tells us it’s her (because of Ella). So:

Ella prefiere mantener su vida privada...
= She prefers to keep her private life...

Without Ella, Prefiere mantener su vida privada... could be his, her, their, or your (formal) private life, depending on context.

Why is it vida privada and not vida personal? Are they the same?

They are close, but not identical:

vida privada = private life, the part of your life you keep away from public view.
vida personal = personal life, more general: relationships, family, non‑work life.

In the context of social media, vida privada is more natural, because it emphasizes the idea of privacy, not just “non‑professional.”

Why is it fuera de instead of just fuera or afuera de?

fuera de = outside of / away from (followed by a noun):
- fuera de la casa = outside the house
- fuera de las redes sociales = outside social media

If you said only fuera, it would sound incomplete here, because it usually needs something: fuera de X.

Afuera de can also mean outside of, but:

fuera de is more neutral and standard, especially in written language.
afuera is often more spatial/physical and more frequent in some Latin American varieties.

For this abstract idea (keeping something off social networks), fuera de is the most natural choice.

Why do we say las redes sociales with las? Could we say just redes sociales?

Both are possible, but they feel slightly different:

las redes sociales = social media as a more definite, known set (all that world of platforms we all recognize).
en redes sociales (without article) is also used, often in a more general or indefinite way, especially in expressions like:
- trabajar en redes sociales
- publicar en redes sociales

In your sentence, fuera de las redes sociales sounds very natural, as if referring to the world of social media platforms as a concrete, well‑known environment.

What exactly does redes sociales mean? Why is redes feminine plural?

red (feminine noun) = network
social (adjective) = social
redes sociales = social networks, the literal basis of what we call social media

Because red is feminine, its plural is redes, and the adjective agrees in number:

red social (singular)
redes sociales (plural)

In practice, las redes sociales = social media (Facebook, Instagram, X, TikTok, etc.) in Spain as well.

Could we say Ella prefiere mantener privada su vida instead of su vida privada?

You can say mantener privada su vida, and it’s grammatically correct, but:

su vida privada is the far more natural and frequent phrase.
Spanish tends to put adjectives after the noun, especially for this kind of fixed expression: vida privada.

mantener su vida privada is idiomatic and smooth.
mantener privada su vida sounds more marked or stylistic, and would be unusual in everyday speech.

Why is it privada and not privado?

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

vida is feminine singular.
So the adjective must be feminine singular: privada.

Other examples:

casa privada (feminine singular)
problema privado (masculine singular)
vidas privadas (feminine plural)

Could we say mantenerse instead of mantener here? What would change?

mantener (non‑reflexive) = to keep / maintain (something).
- mantener su vida privada fuera de... = keep her private life out of...
mantenerse (reflexive) = to keep oneself / stay.
- mantenerse fuera de las redes sociales = to stay off social media (she herself doesn’t use it).

So:

Ella prefiere mantener su vida privada fuera de las redes sociales.
Emphasis: her private life is not exposed there.
Ella prefiere mantenerse fuera de las redes sociales.
Emphasis: she herself prefers not to be on social media.

Both are correct, but they focus on slightly different things.