Restrictive. Nonrestrictive. The terms sound serious and potentially menacing, especially when used to describe clauses. However, restrictive and nonrestrictive clauses are actually pretty simple to understand. Take a look.
What Exactly Do Restrictive and Nonrestrictive Mean?
Let’s start with some definitions.
A restrictive clause is essential to the meaning of a sentence as a whole. If you took out the restrictive clause, the sentence would no longer make sense. Words like that, who, whom, or whose introduce a restrictive clause. These clauses are not set off with commas.
A nonrestrictive clause is not essential to the meaning of a sentence. The sentence will still make sense without the clause. Like restrictive clauses, nonrestrictive clauses can also begin with who, whom, or whose; however, they can also be introduced with which instead of that. These clauses are set off with commas.
*Note that in American English, it’s advised to use that instead of which when introducing a restrictive clause. However, in British English, either word is acceptable for a restrictive clause.
What Do These Clauses Look Like?
Now that we have a general understanding of these clauses, let’s look at some examples:
I prefer milkshakes that are thick since they take longer to consume.
Note how there are no commas separating “that are thick” since this is a restrictive clause.
I prefer thick milkshakes, which take longer to consume, over thin ones that can be slurped through a straw.
Since the phrase “which take longer to consume” can be taken out of the sentence without changing the sentence’s meaning, we know it’s a nonrestrictive clause.
Sometimes a clause may be restrictive or nonrestrictive, depending on the intended meaning. For instance, consider the following examples:
Please don’t make me sit by my cousin Fred!
Please don’t make me sit by my cousin, Fred!
The first sentence implies that the narrator has more than one cousin. Thus, “Fred” is an essential (restrictive) part of the sentence that helps the reader know which cousin the narrator is referring to.
In the second sentence, the narrator has only one cousin, so his name is part of a nonrestrictive clause that can be taken out without changing the sentence’s meaning.
Now you can successfully talk about your milkshake preferences and family relations. Until next grammar time!