Learn Hardcore Spanish (Spain): No me gusta cuando alguien es egoísta con sus amigas; prefiero gente cariñosa. - I don’t like it when someone is selfish with her friends; I prefer affectionate people.

No me gusta cuando… literally = “It is not pleasing to me when…”
me is an indirect object pronoun: to me
the thing that pleases (or doesn’t please) is the grammatical subject, not “I”.

Compare:

Me gusta el café. → Coffee is pleasing to me → I like coffee.
No me gusta cuando llueve. → It is not pleasing to me when it rains. → I don’t like it when it rains.

If you said No gusto, it would mean “I am not pleasing / people don’t like me”, which is a different idea:

No gusto a nadie. → Nobody likes me.

So:

No me gusta (algo) = I don’t like (something).
No gusto = People don’t like me. (different meaning)

Could you add yo and say Yo no me gusta…?

No. Yo no me gusta is ungrammatical.

With gustar:

You can add a clarifying/emphatic phrase with a mí:
- A mí no me gusta cuando… (very natural)
You do not use yo as the subject because yo is not the subject of gustar.

Structure:

A mí / A ti / A él… = prepositional phrase that clarifies who the feeling belongs to
me / te / le… = indirect object pronoun (required)
the thing you like/dislike = subject of gustar

So correct versions are:

No me gusta cuando alguien es egoísta…
A mí no me gusta cuando alguien es egoísta… (stronger emphasis)

But not Yo no me gusta…

Why is it cuando alguien es egoísta and not sea egoísta? When do I use indicative vs. subjunctive after cuando?

After cuando, Spanish uses indicative or subjunctive depending on the meaning:

Indicative = something habitual, general, or real:
- No me gusta cuando alguien es egoísta.
  → talking about a general situation / habit: whenever someone is selfish, I don’t like it.
Subjunctive = future / uncertain / not yet realized event:
- No me gustará cuando alguien sea egoísta conmigo.
  → I won’t like it when someone is selfish with me (in the future).
- Cuando alguien sea egoísta contigo, dímelo.
  → When someone is selfish with you (if that ever happens), tell me.

In your sentence, the speaker is describing a general preference about the world, so es (indicative) is correct.

Why does egoísta end in -a even though alguien can be a man or a woman? Does egoísta change for gender?

Egoísta is one of those adjectives that does not change for gender:

un chico egoísta – a selfish boy
una chica egoísta – a selfish girl
alguien egoísta – someone selfish (could be male or female)

The -a ending here is not “feminine”; it’s just the invariant form of the adjective. It does change for number:

alguien egoísta
personas egoístas

Why is it con sus amigas and not de sus amigas or a sus amigas?

Prepositions change the meaning:

egoísta con alguien = selfish with someone (you don’t share, you don’t help that person)
- Es egoísta con sus amigas. → He/she is selfish with his/her friends.
egoísta de alguien is not idiomatic in this sense. You wouldn’t normally say egoísta de sus amigas.
egoísta a sus amigas is incorrect; egoísta doesn’t take a like that.

So con is the natural preposition to express being selfish towards / in dealings with other people.

Whose friends are sus amigas? Is it “his/her friends” or “their friends”? Could it mean “my friends”?

In this sentence, sus refers to “that person’s” friends — the same person as alguien.

No me gusta cuando alguien es egoísta con sus amigas…
→ I don’t like it when someone is selfish with *their friends.*

Details:

sus is the possessive adjective for él / ella / usted / ellos / ellas / ustedes.
It doesn’t normally refer to “my” friends. For that you’d say mis amigas.

Because alguien is indefinite and could be male or female, in natural English you’d usually translate sus amigas as “their friends” (singular they).

Why amigas (feminine) and not amigos (masculine or mixed)? Is this a Spain-specific thing?

A few points:

Amigas = specifically female friends (group of women).
- sus amigas = “her (female) friends” or “his (female) friends”.
Amigos can mean:
- all-male group, or
- mixed group (traditional “generic masculine”).
Is this Spain-specific?
- No, the grammar is the same across Spanish varieties.
- However, in Spain (and elsewhere) people may choose amigas when they want to highlight that the group is all women, or when context makes that obvious.

So amigas here suggests we’re specifically talking about female friends. If you wanted to be neutral or include men, you’d say amigos.

Why is there a semicolon ; before prefiero gente cariñosa? Could it be a comma or a full stop instead?

In Spanish punctuation, the semicolon works similarly to English:

It separates two closely related clauses that could be separate sentences but feel connected.

Here:

No me gusta cuando alguien es egoísta con sus amigas; prefiero gente cariñosa.

You could also write:

No me gusta cuando alguien es egoísta con sus amigas. Prefiero gente cariñosa. (two sentences)
Using a comma here would be less correct in careful writing, because they are two full clauses.

So the semicolon is stylistic: it shows a strong contrast but keeps both ideas in one “larger” sentence.

Why is it prefiero gente cariñosa without an article? Why not prefiero la gente cariñosa or prefiero una gente cariñosa?

Gente is a bit special:

No article here because we’re talking about people in general / a type of people, not a specific group:
- Prefiero gente cariñosa.
  → I prefer affectionate people (in general).
La gente cariñosa would be more specific, like a known group:
- Prefiero a la gente cariñosa (que conozco).
  → I prefer the affectionate people (the ones we’re talking about).
Una gente cariñosa is possible but more colloquial/limited; gente doesn’t behave like a regular countable noun.

So prefiero gente cariñosa is the most natural way to express a general preference about the type of people you like.

Is gente singular or plural? Why is it gente cariñosa and not gente cariñosas?

Gente is grammatically singular and feminine, even though it refers to a group:

Esta gente es simpática. → verb is singular (es).
La gente cariñosa → adjective cariñosa is feminine singular.

So:

gente cariñosa (✅)
gente cariñosas (❌)

If you want full plural agreement, you’d use personas:

Prefiero personas cariñosas. → I prefer affectionate people.

Should it be prefiero a la gente cariñosa with a? When do I use the “personal a” with gente?

The personal a is used before direct objects that are specific people:

Quiero a mi familia.
Respeto a la gente cariñosa que me rodea.

In your sentence:

Prefiero gente cariñosa. → general type of people, not specific, so no a.

If you make it specific/definite:

Prefiero a la gente cariñosa (de mi entorno).
→ now you have la gente cariñosa = a specific group, and you add a because it’s a direct object referring to people.

So:

no article, no “a” = general type: Prefiero gente cariñosa.
definite article + “a” = specific people: Prefiero a la gente cariñosa.

Why is cuando written without an accent here? What’s the difference between cuando and cuándo?

cuando (no accent) is used in:
- statements:
  - No me gusta cuando alguien es egoísta.
- indirect questions (embedded):
  - No sé cuándo viene. (I don’t know when he’s coming.) → Here it does take an accent because it’s still an interrogative word inside the sentence.
cuándo (with accent) is used in:
- direct questions:
  - ¿Cuándo vienes? (When are you coming?)

In your sentence, cuando introduces a time clause in a statement, so it does not carry an accent:

No me gusta cuando alguien es egoísta… ✅
No me gusta cuándo alguien es egoísta… ❌ (incorrect here)

Could I say No me gusta cuando alguien es egoísta con sus amigos; prefiero personas cariñosas instead? Would that change the meaning?

Yes, you could, and it’s perfectly grammatical:

amigos instead of amigas:
- amigos = male or mixed friends, or generic “friends”.
- amigas = female friends only.
personas cariñosas instead of gente cariñosa:
- gente cariñosa sounds a bit more general and abstract: “the kind of people who are affectionate.”
- personas cariñosas is a bit more concrete, literally “affectionate persons/people”.

Both are natural; the original with gente is slightly more colloquial and generic, which fits this kind of personal preference statement well.