That or Which

S.C. Denton · Apr 29, 2009

Occasionally I'm unsure whether I should use that or which. Is there are hard and fast rule regarding usuage?

Tad Richards · Apr 29, 2009

Which ALWAYS with non-persons. "That" can be used with persons, but I almost never would.

cooeedownunder · Apr 29, 2009

When you are using 'that' and it can be replaced with a comma, use which.

Which is preferable to that.

Eg.

It stops the swarms of mosquitoes that come from the creek, eating us alive.”

It stops the swarms of mosquitoes, which come from the creek, eating us alive.”

eg

That is very kind of you.

Her eyes lit up that moment.

eg

A curve formed on the corner of his lips that he fought hard to stop turning into a smile.

A curve formed on the corner of his lips, which he fought hard to stop turning into a smile.

extortionist · Apr 30, 2009

Here's an explanation from the Chicago Manual of Style:
http://www.chicagomanualofstyle.org/CMS_FAQ/Whichvs.That/Whichvs.That01.html

and another from a random grammar blog:
http://grammar.quickanddirtytips.com/which-versus-that.aspx

Makes sense to me.

S.C. Denton · Apr 30, 2009

extortionist said:
Here's an explanation from the Chicago Manual of Style:
http://www.chicagomanualofstyle.org/CMS_FAQ/Whichvs.That/Whichvs.That01.html

and another from a random grammar blog:
http://grammar.quickanddirtytips.com/which-versus-that.aspx

Makes sense to me.

Thanks everyone. But Extortionist, I'm especially glad you posted the link to the chicago manual of style. It helped me to grasp it better, and now that I have it bookmarked I'll be able to consult it in those doubting times.

dawinsor · Apr 30, 2009

I just want to reiterate that you choose "that" or "which" based on whether the modifier the word introduces is restrictive or nonrestrictive, as the CMS explains. Both of them usually refer to inanimate objects. If you're talking about people, you're almost using some form of "who."

The Lonely One · Apr 30, 2009

Is it first person? If you understand the rule it's okay to break for voice or aesthetic purposes, I think.

Cybernaught · Apr 30, 2009

'That' is restrictive, 'Which' is non-restrictive.

Mad Queen · Apr 30, 2009

'Which' can be used in restrictive clauses as well.

Cybernaught · Apr 30, 2009

Mad Queen said:
'Which' can be used in restrictive clauses as well.

Yeah, but that's just going to confuse everyone (or maybe just me). :Shrug:

Sage · Apr 30, 2009

cooeedownunder said:
When you are using 'that' and it can be replaced with a comma, use which.

Which is preferable to that.

Eg.

It stops the swarms of mosquitoes that come from the creek, eating us alive.”

It stops the swarms of mosquitoes, which come from the creek, eating us alive.”

This is not correct.

There are absolutely times to use "that" instead of "which," and this example is one of them.

You use "that" when the part that comes afterwards lets you know which (haha) of the noun you're talking about.

Above "mosquitos" need more explanation. "It stops the swarms of mosquitos." Unless the context is clear from a previous sentence (which we don't have), we have no idea what mosquitos are being stopped, and the part after "that" lets us know.

However, you could use "which" (with a comma before it, always) if you were to say

"It stops our creek's mosquitos, which eat us alive every summer." Now we know which mosquitos, so the clause afterwards is just extra information.

So another, more obvious, example could be:

"I left the book that I'm reading on the table."
vs.
"I left Summer Knight, which I'm reading, on the table."

The first one "I'm reading" lets you know which book you're talking about, and the second just gives you more info.

davidnowlin · May 5, 2009

There are definite times when one is appropriate and the other is not and there are times when either is appropriate, depending on what you are actually trying to say.

'That' is exclusive and 'which' is inclusive.

If you want to identify something, use 'which'. If you are merely trying to describe it, use 'that'.

This is a ball, which is a round object used in many sports.
This is the ball that my father gave me for my birthday.

With 'which' you are identifying what the ball is. This is a ball. All balls are round objects used in many sports. This is a ball, which is a round object used in many sports.

With 'that' you are simply describing. This is a ball. This happens to be the ball my father gave me. This is the ball that my father gave me.

I have a more in depth discussion of this on my website.
http://www.becausewehaveto.com/grammartraps1.htm#thatwhich

Bufty · May 5, 2009

I think you have your wires crossed.

davidnowlin said:
There are definite times when one is appropriate and the other is not and there are times when either is appropriate, depending on what you are actually trying to say.

'That' is exclusive and 'which' is inclusive.

If you want to identify something, use 'which'. If you are merely trying to describe it, use 'that'.

This is a ball, which is a round object used in many sports.
This is the ball that my father gave me for my birthday.

With 'which' you are identifying what the ball is. This is a ball. All balls are round objects used in many sports. This is a ball, which is a round object used in many sports.

With 'that' you are simply describing. This is a ball. This happens to be the ball my father gave me. This is the ball that my father gave me.

I have a more in depth discussion of this on my website.
http://www.becausewehaveto.com/grammartraps1.htm#thatwhich

davidnowlin · May 5, 2009

Bufty said:
I think you have your wires crossed.

Hmmm... Perhaps the word 'identify' wasn't the most illustrative, but I don't have my wires crossed. If I tell you what a ball is, that's an identification. I'm identifying the entire class 'ball.'

This is a ball. There are many balls. All balls are things one throws. A ball is a round thing one throws. This is a ball, which is a round thing one throws.

If I tell you something about this ball that makes it different from other balls, that's a description. I'm describing this ball, not telling you what a ball is.

This is a ball. There are many balls. This is the one my father gave me. This is the ball that my father gave me.

I can understand how there might be confusion if you read 'identify' in a slightly different way. As in, "I'm identifying which ball, out of many possible balls, that I'm talking about." But the point here is to convey that when using 'that' you're talking about a particular attribute of a thing and when using 'which' you are talking about what that thing has in common with all other examples of its class.

If it makes it clearer for you, delete 'identify' from the original explanation and replace it with 'define.'

__________________________
Update:

Okay. Upon further reflection, I'm convinced that you're right. Identify could apply to either situation. "This is a ball, which is a thing one throws," identifies 'ball' and "This is the ball that my father gave me," identifies 'this ball.' 'Identify' was the wrong word to use. Define would definitely be better. Inclusive clauses (or 'which' clauses) define the class. All balls are... whatever. Exclusive clauses ('that' clauses) describe a particular member of the class. "This ball is... whatever."

dpaterso · May 6, 2009

Sorely tempted to say "you're talking a load of balls"

The way I've always figured it, when there's a choice of many implied, use "which". If you're pointing out one specific instance, use "that" instead.

-Derek

davidnowlin · May 6, 2009

dpaterso said:
Sorely tempted to say "you're talking a load of balls"

Huh huh... he said 'balls.'

dpaterso said:
The way I've always figured it, when there's a choice of many implied, use "which". If you're pointing out one specific instance, use "that" instead.

Unless I misunderstand you, we're pretty much talking about the same thing. A 'which' clause applies the descriptor to the entire class being described (many) and a 'that' clause applies the desciptor to only a single member of the class (one specific instance).

Mad Queen · May 6, 2009

From the Oxford Dictionary of English:

Is there any difference between the use of that and which in sentences such as any book that gets children reading is worth having, and any book which gets children reading is worth having? The general rule is that, in restrictive relative clauses, where the relative clause serves to define or restrict the reference to the particular one described, which can replace that. However, in non-restrictive relative clauses, where the relative clause serves only to give additional information, that cannot be used: this book, which is set in the last century, is very popular with teenagers but not this book, that is set in the last century, is very popular with teenagers. In US English it is usually recommended that which be used only for non-restrictive relative clauses.

I hope this isn't too long to quote.

davidnowlin · May 6, 2009

Mad Queen said:
this book, which is set in the last century, is very popular with teenagers but not this book, that is set in the last century, is very popular with teenagers.

This, obviously, is a different case. The rule I was trying to describe (in an easily understandable way, I hoped) only deals with classes. In this example, we're not talking about a class at all. 'This book' automatically identifies it as a single object, rather than a single member of a larger class of objects (such as 'a book'). But, you'll notice, 'which' is still used to define the whole of the thing being described. Where we're only talking about one book, the whole of the thing being described is a single object. To go back to balls (heh heh):

This ball, which is a round object one can throw, is green.

You're still defining 'ball.' It's the same with the book up there. You're not defining all books, but you are defining 'this book' as one that is set in the last century.

Of course the best way to differentiate is to use the terms 'restrictive' and 'non-restrictive' but even I have trouble remembering precisely what those mean and which is which. I'm not sure they're helpful to the novice who asked the question. But the basic concept can, I think, best be illustrated with a well-known military chant.

This is my rifle. There are many like it, but this one is mine.

The difference between restrictive and non-restrictive comes in that 'there are many like it' part.

This is the rifle that is mine. This is restrictive, and consequently we use 'that'. We know it's restrictive because there are many rifles we could be talking about, but we are restricting our description to this one particular example. This description, in other words, does not apply to all rifles, but only to 'this one'.

This is my rifle, which is a weapon used for killin' folk. This is non-restrictive and we use 'which'. We know it's non-restrictive because the descriptive clause applies to all rifles. It's not restricted to 'this one' in particular. This is my rifle. There are many like it. They are all weapons used for killin' folk.

This rifle, which is a weapon used for killin' folk, is mine. Still non-restrictive. Even though this time we're only talking about a single rifle and not the whole class of objects. This one is non-restrictive, though, because it applies to the entire class being discussed. It just happens to be a class of one. This one. This is a rifle. There is only one like it. It's a weapon used for killin' folk. And it's mine.

I'm not sure if that was helpful at all, and I'm not sure it's the way the grammar books describe the difference, but it's the way I've always understood it.

The real trouble comes when it's not so obvious that a thing is meant to be restrictive or non-restrictive. In some cases, as I said before, either 'that' or 'which' is appropriate, but choosing one over the other will change the meaning of the sentence.

Let's take the first example that was posted.

It stops the swarms of mosquitoes that come from the creek, eating us alive.”

It stops the swarms of mosquitoes, which come from the creek, eating us alive.”

Sage said that this was not correct and, though I agree that there was quite a bit wrong in this first comment, I do think that either of these sentences is grammatically flawless. They just don't mean the same thing.

The first one (It stops the swarms of mosquitoes that come from the creek, eating us alive) is describing a particular set of 'swarms of mosquitoes'. There are many swarms of mosquitoes. Some of them come from the creek eating us alive. It stops those swarms.

The second one (It stops the swarms of mosquitoes, which come from the creek, eating us alive) is describing a particular set of 'swarms of mosquitoes' that has already been defined. The speaker of this sentence knows his audience understands that he's not standing in Mississippi talking about swarms of mosquitoes in Tokyo. He's talking about the swarms of mosquitoes that are relevant to his life and only those swarms. And he's describing all of them. There are many swarms of mosquitoes, but I'm speaking only of a particular subset of swarms. All of those swarms come from the creek, eating us alive.

The problem is the article. 'It stops the swarms of mosquitoes...' We know we're talking about a definite set of swarms. There's just no way to distinguish between whether we intend that to be a subset of the larger class 'swarms of mosquitoes' or a class of its own. And without that information, there's no way to tell if the description is restrictive or non-restrictive. That is... until you decide to use 'that' or 'which'. Using one or the other makes that decision and conveys it to your reader. That is why it's important to know the difference between the two.

Bufty · May 6, 2009

.

davidnowlin said:
This, obviously, is a different case. The rule I was trying to describe (in an easily understandable way, I hoped) only deals with classes. In this example, we're not talking about a class at all. 'This book' automatically identifies it as a single object, rather than a single member of a larger class of objects (such as 'a book'). But, you'll notice, 'which' is still used to define the whole of the thing being described. Where we're only talking about one book, the whole of the thing being described is a single object. To go back to balls (heh heh):

This ball, which is a round object one can throw, is green.

You're still defining 'ball.' It's the same with the book up there. You're not defining all books, but you are defining 'this book' as one that is set in the last century.

Of course the best way to differentiate is to use the terms 'restrictive' and 'non-restrictive' but even I have trouble remembering precisely what those mean and which is which. I'm not sure they're helpful to the novice who asked the question. But the basic concept can, I think, best be illustrated with a well-known military chant.

This is my rifle. There are many like it, but this one is mine.

The difference between restrictive and non-restrictive comes in that 'there are many like it' part.

This is the rifle that is mine. This is restrictive, and consequently we use 'that'. We know it's restrictive because there are many rifles we could be talking about, but we are restricting our description to this one particular example. This description, in other words, does not apply to all rifles, but only to 'this one'.

This is my rifle, which is a weapon used for killin' folk. This is non-restrictive and we use 'which'. We know it's non-restrictive because the descriptive clause applies to all rifles. It's not restricted to 'this one' in particular. This is my rifle. There are many like it. They are all weapons used for killin' folk.

This rifle, which is a weapon used for killin' folk, is mine. Still non-restrictive. Even though this time we're only talking about a single rifle and not the whole class of objects. This one is non-restrictive, though, because it applies to the entire class being discussed. It just happens to be a class of one. This one. This is a rifle. There is only one like it. It's a weapon used for killin' folk. And it's mine.

I'm not sure if that was helpful at all, and I'm not sure it's the way the grammar books describe the difference, but it's the way I've always understood it.

The real trouble comes when it's not so obvious that a thing is meant to be restrictive or non-restrictive. In some cases, as I said before, either 'that' or 'which' is appropriate, but choosing one over the other will change the meaning of the sentence.

Let's take the first example that was posted.
It stops the swarms of mosquitoes that come from the creek, eating us alive.”
It stops the swarms of mosquitoes, which come from the creek, eating us alive.”
Sage said that this was not correct and, though I agree that there was quite a bit wrong in this first comment, I do think that either of these sentences is grammatically flawless. They just don't mean the same thing.

The first one (
It stops the swarms of mosquitoes that come from the creek, eating us alive) is the writer deciding for his own reasons to specifically identify the swarms of mosquitoes concerned as those coming from the creek~~describing a particular set of 'swarms of mosquitoes'. There are many swarms of mosquitoes. Some of them come from the creek eating us alive. It stops those swarms.~~

The second one It stops the swarms of mosquitoes, which come from the creek, eating us alive) is describing a particular set of 'swarms of mosquitoes' that has already been defined. The speaker of this sentence knows his audience understands that he's not standing in Mississippi talking about swarms of mosquitoes in Tokyo. He's talking about the swarms of mosquitoes that are relevant to his life and only those swarms. And he's describing all of them. There are many swarms of mosquitoes, but I'm speaking only of a particular subset of swarms. All of those swarms come from the creek, eating us alive. is simply the writer deciding for his own reasons to add extra information about the mosquitoes.

The problem is the article. 'It stops the swarms of mosquitoes...' We know we're talking about a definite set of swarms. There's just no way to distinguish between whether we intend that to be a subset of the larger class 'swarms of mosquitoes' or a class of its own. And without that information, there's no way to tell if the description is restrictive or non-restrictive. That is... until you decide to use 'that' or 'which'. Using one or the other makes that decision and conveys it to your reader. That is why it's important to know the difference between the two.

davidnowlin · May 6, 2009

Bufty said:
.

davidnowlin said:

The first one (
[/s]It stops the swarms of mosquitoes that come from the creek, eating us alive) is the writer deciding for his own reasons to specifically identify the swarms of mosquitoes concerned as those coming from the creek~~describing a particular set of 'swarms of mosquitoes'. There are many swarms of mosquitoes. Some of them come from the creek eating us alive. It stops those swarms.~~

Click to expand...

I have to say, I'm at a bit of a loss as to how to take your response to my post. If you're trying to say that a simpler explanation was possible, I'm not sure I disagree, but as my sister-in-law can often be heard admonishing her four-year-old, I'd suggest that you 'use your words.' I'm not sure it was necessary to make the sort of statement your post did.

And, additionally, I would point out that your simpler explanation (if that's what you intended) doesn't really guide a writer who doesn't understand the distinction between these words and the ways they are used. Maybe my explanation didn't either, but I did at least attempt it, rather than jotting down a simplistic platitude.

If you were trying to say that a writer is at his liberty to use whichever of these he wants for whatever purpose he wants, I'd have to agree and disagree. Anyone can put anything he wants on a piece of paper. But there is a right and a wrong way to use words if you want to be understood by other people who use those words.

On the whole, I just thought your post was rude and un-called for.

Bufty · May 6, 2009

Sorry if you feel that way, but this particular forum is for basic questions and the basic usage is simpler to grasp if simple examples are given.

Further info and research can be done by those wishing to do so, but my ammendment to your post (and the examples of others) are not simplistic platitudes. They show a beginner when to use 'which' or 'that' depending upon what information they wish to convey and what emphasis they wish to give to the information.

dpaterso · May 6, 2009

I was going to mention the basic questions and answers thing, but perhaps in not such a potentially agitating manner.

Let's put the thread to bed -- the original poster has enough info to be getting on with.

-Derek

That or Which

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Where have the last ten years gone?

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