# That/Which Rule **URL:** \ **Category:** Factual Questions\ **Created:** [November 13, 2015, 4:56pm UTC](https://boards.straightdope.com/t/that-which-rule/737477 "2015-11-13T16:56:40Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Sir\_T-Cups](https://avatars.discourse-cdn.com/v4/letter/s/ed655f/32.png) [@Sir\_T-Cups](https://boards.straightdope.com/u/Sir_T-Cups)\ **Post date:** [November 13, 2015, 4:56pm UTC](https://boards.straightdope.com/t/that-which-rule/737477/1 "2015-11-13T16:56:40Z")
Can someone give me an easy way to determine whether I should use “that” or “which” in a sentence? In my new job (!!) I find myself explaining things a lot via my writing, and as a habit I always cntrl +F and find all my “thats” and delete most of them because I have a horrible habit of putting them in my writing. That fact nonwithstanding, I am seeing I use “that” to explain pretty much everything, and I know there’s a rule when to use “that” and when to use “which” and I’ve looked online and the explanations are technical and difficult and confusing. Does anyone have an easy way for me to determine which one I should use? ---
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [November 13, 2015, 5:08pm UTC](https://boards.straightdope.com/t/that-which-rule/737477/2 "2015-11-13T17:08:42Z")
If your work has a manual of style, use it. Otherwise, do what sounds right. There are rules, sure; there are lots of different rules, all contradictory, none of which are objectively correct or incorrect. Now watch this thread degenerate into “My rule is best!” “No, mine!” “Illiterate imbecile!” “Babbling buffoon!” ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [November 13, 2015, 5:13pm UTC](https://boards.straightdope.com/t/that-which-rule/737477/3 "2015-11-13T17:13:12Z")
Rule of thumb, meaning this will get you through 90+% of all examples. Use a comma before which. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [November 13, 2015, 5:17pm UTC](https://boards.straightdope.com/t/that-which-rule/737477/4 "2015-11-13T17:17:56Z")
The basic rule is actually pretty simple. - If the clause being introduced is essential to the meaning of the sentence, then use “that.” - If the clause is not necessary, but merely provides additional information, use “which.” 1. The bicycle that is red is next to the house. Here you are giving information about a specific bicycle, the one that is red. You are distinguishing it from other bicycles that happen to be other colors. 1. The bicycle, which is red, is next to the house. Here you are mainly interested in specifying where the bicycle is. The clause is giving additional information that is not essential for identifying the bicycle. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [November 13, 2015, 5:26pm UTC](https://boards.straightdope.com/t/that-which-rule/737477/5 "2015-11-13T17:26:44Z")
> [@Derleth](#): > > If your work has a manual of style, use it. Otherwise, do what sounds right." The major manuals of style for American English, the Chicago Manual of Style and the Associated Press Stylebook, give the basic rule as I have stated it. This is for American English; the distinction is often not made in British English. This said, the rule IMO is often overemphasized, and it is often not followed in informal writing. If you are worried about people criticizing your usage, follow the rule. If not, it’s not strictly necessary. ---
**Author:** ![Alessan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alessan/32/465_2.png) [@Alessan](https://boards.straightdope.com/u/Alessan)\ **Post date:** [November 13, 2015, 5:52pm UTC](https://boards.straightdope.com/t/that-which-rule/737477/6 "2015-11-13T17:52:30Z")
> [@Exapno\_Mapcase](#): > > Rule of thumb, meaning this will get you through 90+% of all examples. > > Use a comma before which. That’s the rule I use, too. It serves me well. Just make sure you don’t do it reflexively and that it’s not, say, after a comma used as part of an interjection, as in, “Tom thought, unlike what everyone was saying, that it was a pretty good idea.” ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [November 13, 2015, 7:20pm UTC](https://boards.straightdope.com/t/that-which-rule/737477/7 "2015-11-13T19:20:59Z")
> [@Alessan](#): > > That’s the rule I use, too. It serves me well. > > Just make sure you don’t do it reflexively and that it’s not, say, after a comma used as part of an interjection, as in, “Tom thought, unlike what everyone was saying, that it was a pretty good idea.” True, but nobody would say “Tom thought which it was a pretty good idea.” Some that’s and which’s are not interchangeable no matter where in the sentence they are. ---
**Author:** ![lance\_strongarm](https://avatars.discourse-cdn.com/v4/letter/l/87869e/32.png) [@lance\_strongarm](https://boards.straightdope.com/u/lance_strongarm)\ **Post date:** [November 13, 2015, 7:31pm UTC](https://boards.straightdope.com/t/that-which-rule/737477/8 "2015-11-13T19:31:06Z")
> [@Exapno\_Mapcase](#): > > Rule of thumb, meaning this will get you through 90+% of all examples. > > Use a comma before which. 'Zactly. And if the comma doesn’t make it better, use that, with no comma, instead. ---
**Author:** ![Sir\_T-Cups](https://avatars.discourse-cdn.com/v4/letter/s/ed655f/32.png) [@Sir\_T-Cups](https://boards.straightdope.com/u/Sir_T-Cups)\ **Post date:** [November 13, 2015, 7:42pm UTC](https://boards.straightdope.com/t/that-which-rule/737477/9 "2015-11-13T19:42:37Z")
I like the comma rule and it seems simple enough. I send all of my stuff through an editor anway, so if he doesn’t speak up about it I’ll go with the comma rule. I doubt I would have been critisized, I just noticed how often “that” came up and I knew at least SOME of them were wrong You guys rock! Thanks! ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [November 13, 2015, 8:52pm UTC](https://boards.straightdope.com/t/that-which-rule/737477/10 "2015-11-13T20:52:22Z")
Boy do I have a bad habit to break. ---
**Author:** ![dasmoocher](https://avatars.discourse-cdn.com/v4/letter/d/dbc845/32.png) [@dasmoocher](https://boards.straightdope.com/u/dasmoocher)\ **Post date:** [November 13, 2015, 10:29pm UTC](https://boards.straightdope.com/t/that-which-rule/737477/11 "2015-11-13T22:29:19Z")
> [@LSLGuy](#): > > Boy do I have a bad habit to break. Which one? That one. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [November 13, 2015, 11:19pm UTC](https://boards.straightdope.com/t/that-which-rule/737477/12 "2015-11-13T23:19:20Z")
The one which prefers which in almost all circumstances. That one. ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [November 13, 2015, 11:40pm UTC](https://boards.straightdope.com/t/that-which-rule/737477/13 "2015-11-13T23:40:36Z")
I’ve heard the rule as: “If ‘that’ gives the right meaning, use it; if not, use ‘, which’.” Seems to work. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [November 14, 2015, 12:20am UTC](https://boards.straightdope.com/t/that-which-rule/737477/14 "2015-11-14T00:20:26Z")
> [@Exapno\_Mapcase](#): > > Rule of thumb, meaning this will get you through 90+% of all examples. > > Use a comma before which. The problem with this is that it presupposes knowledge of when to use a comma, which often is sadly lacking. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [November 14, 2015, 1:17am UTC](https://boards.straightdope.com/t/that-which-rule/737477/15 "2015-11-14T01:17:12Z")
> [@Colibri](#): > > The problem with this is that it presupposes knowledge of when to use a comma, which often is sadly lacking. You lost me. “Use a comma before which” as a rule is the exact opposite of needing to know when a comma is required. ---
**Author:** ![Loopus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/loopus/32/15343_2.png) [@Loopus](https://boards.straightdope.com/u/Loopus)\ **Post date:** [November 14, 2015, 1:27am UTC](https://boards.straightdope.com/t/that-which-rule/737477/16 "2015-11-14T01:27:15Z")
Here’s Merriam-Webster editor Kory Stamper’s take on it: [- YouTube](https://www.youtube.com/watch?v=N1aWStx9O2Q) ---
**Author:** ![Acsenray](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/acsenray/32/4519_2.png) [@Acsenray](https://boards.straightdope.com/u/Acsenray)\ **Post date:** [November 14, 2015, 1:48am UTC](https://boards.straightdope.com/t/that-which-rule/737477/17 "2015-11-14T01:48:28Z")
> [@Exapno\_Mapcase](#): > > You lost me. “Use a comma before which” as a rule is the exact opposite of needing to know when a comma is required. Right. What it doesn’t tell you is when to use “which.” The rule is as given above: if removing the clause would change the meaning of the sentence, use “that” (restrictive clause). If removing it would not change the meaning, use commas and “which” (nonrestrictive clause). ---
**Author:** ![Siam\_Sam](https://avatars.discourse-cdn.com/v4/letter/s/d78d45/32.png) [@Siam\_Sam](https://boards.straightdope.com/u/Siam_Sam)\ **Post date:** [November 14, 2015, 1:55am UTC](https://boards.straightdope.com/t/that-which-rule/737477/18 "2015-11-14T01:55:29Z")
American Heritage Dictionary has a good [Usage Note](https://www.ahdictionary.com/word/search.html?q=that) on this. I’ve also noticed British usage often uses “which” instead of “that.” ---
**Author:** ![Acsenray](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/acsenray/32/4519_2.png) [@Acsenray](https://boards.straightdope.com/u/Acsenray)\ **Post date:** [November 14, 2015, 2:21am UTC](https://boards.straightdope.com/t/that-which-rule/737477/19 "2015-11-14T02:21:41Z")
> [@Siam\_Sam](#): > > American Heritage Dictionary has a good [Usage Note](https://www.ahdictionary.com/word/search.html?q=that) on this. > > I’ve also noticed British usage often uses “which” instead of “that.” American lawyers and judges also overuse “which.” ---
**Author:** ![Loopus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/loopus/32/15343_2.png) [@Loopus](https://boards.straightdope.com/u/Loopus)\ **Post date:** [November 14, 2015, 2:34am UTC](https://boards.straightdope.com/t/that-which-rule/737477/20 "2015-11-14T02:34:17Z")
> [@Acsenray](#): > > American lawyers and judges also overuse “which.” I think that “which” sounds naturally “smart” to people. I taught remedial English writing in college, and I had a student once who tried to insert “in which” everywhere, I theorize because he was uncomfortable with formal writing and thought that “which” sounded intelligent and formal somehow. [Next page](https://boards.straightdope.com/t/that-which-rule/737477.md?page=2)