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 is used when it comes as an antecedent to what it 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 what its’ been said previously, the person spoken about or the (who it refers to in number). 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 relative 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, los que te compró Elizabeth, son bonitos.
The apartments, the ones Elizabeth bought, are pretty.
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, en la cual hay un jarrón encima. My sister is setting the table, in which there is a vase on top.