Relative pronouns in Spanish are words that connect clauses to give more information about previously mentioned people, things, or issues. You use them to connect ideas in one sentence and avoid repetition. Relative pronouns are the pronouns that are used to connect sentences, and they are used to refer back to a noun, pronoun or phrase that was talked about previously.
Relative pronouns are used to connect sentences to clarify and add information. The most common ones are Que, Quien.
Jennifer entra en la casa. La casa es mía.
Jennifer entra en la casa que es mía.
Que – Quien
Que can refer to a person or thing, and it comes right after the antecedent, the noun it is trying to clarify. Usually, it adds information about the previous statement.
La mujer que vive en esa casa es mi hermana. The woman who lives in that house is my sister.
Que- It can refer to a thing, person or place and means: that, which, who, or whom.
Quien- It can only refer to a person and it means who or whom.
When using Quien, it must match in number the person spoken about previously (the person it refers to). If the previous word is used in singular, you would use quien, and if it is plural, you will use quienes.
El Que and its relative forms: la que, los que, las que, are used in agreement with gender and number. El que, is usually used when there is distance between the antecedent and the relative pronoun. It can also be used with prepositions such as sin, por and para, instead of just Que.
Los apartamentos que te compró Elizabeth son bonitos.
The apartments that Elizabeth bought for you are pretty.
El Cual
El cual and its relative forms: la cual, los cuales, las cuales, must also agree in number and gender when used. They are used when there is more distance between the antecedent and the relative pronoun.
Mi hermana está poniendo la mesa, sobre la cual hay un jarrón. My sister is setting the table, on which there is a vase.