Defining and non-defining relative clauses

Relative clauses are subordinate clauses using a relative pronoun, for example: que, quien, el cual, cuyo. Relative adverbs cuando, como, or donde can also introduce a relative clause. 

These clauses can add two different types of information about the noun (present in the main clause) they are modifying:

• defining
• non-defining

Defining relative clauses: "relativas especificativas"

Defining relative clauses are called "subordinadas relativas especificativas" in Spanish. They give important information about the noun and without this clause we would lose part of the meaning of the sentence. They define the noun; the information in the clause  differentiates the element referred to from the rest. Let's see some examples:

Here, the subordinate clause refers "only" to the students who passed the exam (and not any of the other students) - it specifies the exact type of student, it defines them.

Here, the subordinate clause refers to a specific necklace: the one she was wearing yesterday (not any other that she may own or have worn on any other day) - it is defining exactly which necklace by giving specific information that differentiates it from any other. 

Here are other examples with other relative pronouns and relative adverbs:

Relative clauses that use cuando, donde, como can be substituted by que/cual, with the same meaning, for example, you can also say:

Non-defining relative clauses: "relativas explicativas"

Non-defining relative clauses are called "subordinadas relativas explicativas" in Spanish. They convey information about the noun that is supplementary, extra or even "redundant", i.e. it does not differentiate the noun, it is not information that defines the noun. If we were to omit the clause, the sentence would still make sense and there would be no important information missing. Notice how with "explicativas" there are always commas. Let's see some examples:

This sentence does not refer to a sub-set of friends that I really love, here it refers to all my friends, and gives the extra information that I love them all. 

This sentence is not differentiating one necklace among many, ;it is just extra information about an innate quality of that necklace.

Here, I am giving supplementary generic information about the place but I am not differentiating it from other places.

Here, I am not differentiating that moment from another moment, it is just additional information about that same moment.

It's important to note two important points about non-defining relative clauses:

• They contain redundant information in the sentence.
• They always need commas.

How to use quien/quienes

The relative pronouns quien/quienes are only interchangeable with que in relative clauses in some cases.

Bear in mind that quien/quienes can always be used in non-defining clauses (explicativas),  but to be used in defining clauses (especificativas) the relative must be used with a preposition, otherwise you need que. For example:

Non-defining (explicativa):

Non-defining (explicativa):

Defining (especificativa):

Defining (especificativa):

How to use el cual/los cuales

As with quien/quienes, the relative pronouns el cual, la cual, los cuales, las cuales are interchangeable with que in relative clauses in some cases. The same rule as for quien/quienes, i.e. the need of a preposition in defining clauses (especificativas), applies to el cual, la cual, los cuales, las cuales.

For example:

non-defining (explicativa):

non-defining (explicativa):

non-defining (explicativa):

defining (especificativa):

defining (especificativa):

When there is no antecendent 

Some relative clauses don't have a "visible" antecedent, i.e. the noun the relative is referring to. This often happens with cuando, como, donde. See some examples:

Here, the sentence implies "any time you want", but "time" is not explicitly mentioned in the sentence:

With an antecedent this would be:

This is the same as saying:

With the relative pronouns que and quien this is also possible. The antecent is not explicit because it's understood: 

The non-mentioned antecedent for these would be:

"...la persona que..." (the person who...)

Lessons with more detail on (Defining and non-defining relative clauses)

• Que/ el cual/ la cual/ los cuales/ quien/ quienes = who, that, which (Spanish relative pronouns)
• Spanish relative clauses with the indicative and the subjunctive (subordinate relative clauses)
• Using cuyo, cuya, cuyos, cuyas to say whose + noun (relative adjective)
• Using lo que = what, which, that which, the thing that (Spanish relative pronouns)
• Using preposition a and de + el que, la que, los que, las que = to/of/from/about which/who (relative pronouns)
• Using preposition [except a and de] + el que, la que, los que, las que = with/for/on/in/from which (relative pronouns)
• Using Spanish relatives el que, la que, los que, las que = the one/ones who/that (relative pronouns)
• Using [preposition] + lo que = with, for, on + what (relative pronouns)