[Hoot]
You know what I love?
Ducks.
There’s nothing more peaceful than watching ducks on a warm day as the wind jostles your
hair and the occasional quack in the distance meets your ears like a sweet lullaby.
But you know what I don’t love?
Trying to remember the difference between that and which.
Hi, I’m Gabriel from the OWL, and today we’re going to distinguish between two very
pesky words that can confuse our sentences and frustrate our readers.
We use that and which depending on whether the clause it introduces is restrictive or
non-restrictive.
A restrictive clause means the information is necessary to the preceding noun.
When we have a restrictive clause, we use that.
Let’s look at some examples now.
Take this sentence: Ducks that skim the surface for food are called “dabbling ducks.”
Because there are different types of ducks, the “that” clause is necessary.
Here’s another one: The duck that nests under my porch just laid eggs last week.
In this case, we’re also identifying a specific duck based on its behavior: there are many
ducks in the world, but just one lives under my porch.
Without the information in the restrictive clause, we would be talking about any duck.
Adding a restrictive clause and using that adds the specificity the sentence requires.
One more: I have a waffle maker that makes waffles in the shape of a duck.
Once again, if we ended the sentence at “I have a waffle maker,” we would be missing
crucial information—the whole point of the sentence is that there is something special
about this waffle maker.
Now let’s look at when we use which.
We use which when the information isn’t necessary to the sentence, that is, it’s
a non-restrictive clause.
There’s another important distinction between restrictive and non-restrictive clauses: we
use commas to separate the non-restrictive clauses from the rest of the sentence.
Take this sentence: Male mallard ducks, which have green heads, are called “drakes.”
Because all male mallard ducks have green heads, the added information isn’t necessary
to the sentence.
Also notice the commas surrounding the clause.
Here’s another one: The Ugly Duckling, which was my favorite story as a child, is about
a duck growing up and realizing it’s a swan.
Once again, the information about the story being my favorite isn’t necessary to the
sentence, so we use a non-restrictive clause and “which.”
One more: My car, which I bought used from my neighbor, has duck bumper stickers.
The information about me buying the car from my neighbor isn’t crucial information, so
it’s a non-restrictive clause.
Now, let’s look at a sentence where you might use that or which.
What’s the difference here?
In the first sentence, the implication is that I have multiple ducks, and using “that”
specifies which duck I’m talking about.
For the second sentence, we understand I only have one duck, and the sound it makes is added
information.
See the difference?
Before we end, let’s take a moment to practice.
Take a look at these sentences and see whether they need that or which.
By now, hopefully it’s clearer how to use that and which in a sentence.
The distinction between these two words may be small, but it can nevertheless have big
ramifications for your sentence’s meaning.
It sort of reminds me of the delicate interplay of ripples that form on the surface of my
favorite pond when a few good pieces of bread hit the water… it’s really almost… enchanting,
when you think about it…Now, then.
If you’ll excuse me, I have some very important work to get back to.
Thanks for watching.