A little more to say
Adding detail with “who” or “that”
Relative clauses
Add information identifying or describing a person or thing.
The pattern
- Que often means who/that/which; donde refers to a place.
- Known thing: indicative. A sought or hypothetical thing may use subjunctive.
Busco un piso que tenga balcón.
I am looking for an apartment with a balcony.
Why it works: Tenga describes a requirement for an apartment you have not yet identified.
Notice the difference
Vivo en un piso que tiene balcón.
I live in an apartment that has a balcony.
Why it works: Tiene describes a specific apartment that exists in the speaker’s experience.
One thing to watch for
Do not choose subjunctive just because you see un or busco. The question is whether you are describing something known or a desired, unidentified possibility.