By Allison VanNest of Grammarly.com
If you’re unsure about whether to use that or which in a sentence, you’re not alone in your confusion. According to Grammar Girl (AKA Mignon Fogarty), it’s one of the questions she gets asked most frequently.
This simple question has a surprisingly technical answer, so grab a caffeinated beverage and get comfortable.
Let’s start with some definitions. That, which, and who are all relative pronouns that can be used to introduce adjective clauses. Remember, a clause is a group of words that work together to perform a specific function in a sentence. In the case of adjective clauses, the group of words describes a noun.
- A painting that depicts a grouping of everyday objects is called a still life.
- The awards show, which was held at a new venue this year, was a huge disaster.
Notice that some of the bolded clauses are set off by commas while others aren’t. That’s because an adjective clause can be either restrictive or non-restrictive. A restrictive clause is essential to a sentence; without the clause, the sentence wouldn’t make sense anymore. Example #1 contains a restrictive clause. If we take away the clause, all we’re left with “A painting is called a still life.” Since not all paintings are still life, we know that we’ve lost an essential piece of the puzzle.
A non-restrictive clause, on the other hand, contains information that isn’t necessary to understanding the meaning of a sentence. It may add value or nuance, but the facts remain the same even if we remove it. Example #2 contains a non-restrictive clause; without it, the reader still knows that the awards show was a disaster.
Restrictive clauses begin with that, while non-restrictive clauses begin with which. Furthermore, non-restrictive clauses need to be set off with commas. If you’re not sure whether a clause is restrictive, try taking it out and reading the sentence aloud. If it still makes sense and means what you intend to say, the clause is non-restrictive. If not, it’s a restrictive clause.
To add another wrinkle to the issue, adjective clauses that refer to people can begin with either who or that depending on the circumstances. Usually, you’ll use who, but if you have a nonrestrictive clause referring to a generic person or group of people (e.g. “girls that wear glasses” or “doctors that specialize in pediatric medicine”) that is also acceptable. If you’re unsure, however, just stick with who when referring to people.
Specific person, nonrestrictive clause: Mary, who enjoys opera and ballet, bought season tickets to the performing arts center.
Specific person, restrictive clause: The old man who lives down the street has a beautiful garden.
Generic person, nonrestrictive clause: Comedians, who are larger than life onstage, are often quiet and reserved off the stage.
Generic person, nonrestrictive clause: Students who/that eat breakfast before studying retain more information.
Still scratching your head? Here’s a handy chart:
|Things and Places||That||Which|
|Specific Person or People||Who||Who|
|Generic Person or People||Who, That||Who|
These rules may seem overwhelmingly complicated at first, but with practice it will become second-nature. Until then, an automated grammar checker is your best friend. While using the wrong relative pronoun isn’t the end of the world, there will always be sticklers out there who are more than happy to point out even minor mistakes. Mastering these commonly confused words—and being able to explain why you used one instead of the other, if asked by a reader, editor, or client—will only contribute to the overall professionalism of your writing.
What questions do you have? Ask them in comments.
About the Author: A self-proclaimed word nerd, Allison VanNest works with Grammarly to help perfect written English. Connect with Allie, the Grammarly team, and more than ONE MILLION Grammarly Facebook fans at www.facebook.com/grammarly.
Go ahead and tweet this to your network – thanks!