What does `'s` mean in "What CPU's will it run on?"?



Does it indicate a possessive adjective or just a plural noun? If noun, why it is not CPUs (without apostrophe)?

Windows CE 2.0 presentation: What CPU's will it run on?


Posted 2016-08-02T20:12:06.407

Reputation: 791

86Because inability to punctuate isn't a compile-time error in English. ;) – Wildcard – 2016-08-03T00:01:41.233

14You have discovered the Grocer's apostrophe - Google it and smile :-) – Mawg says reinstate Monica – 2016-08-03T08:38:01.127


@Wildcard Actually, using an apostrophe in plurals of initialisms is considered correct by well-respected style guides. And it's always considered correct when pluralizing single letters ("Mind your p's and q's."). See choster's answer.

– David Richerby – 2016-08-03T10:32:44.130

Is the author Dutch? :) – CompuChip – 2016-08-05T06:12:53.510

@CompuChip Russian actually ;-) – aryndin – 2016-08-05T07:22:38.107

2Interesting. In Dutch we use the apostrophe the other way around - it's not there for the possessive ("Peters boek" instead of "Peters book") but we do use it for plural of nouns ending in a vowel ("baby's" instead of "babies"). Therefore a lot of native speakers have the tendency to form plurals in English with an apostrophe. – CompuChip – 2016-08-05T08:15:17.957

2@Mawg I think there needs to be a new name for cases when people call something a "grocer's apostrophe" when it's not one, as is the case here. – Jon Hanna – 2016-08-05T10:28:51.170

@CompuChip Except when you use it at the beginning of a name, like 's-Gravenhage and 's-Hertogenbosch. That really messes with English brains. ;) – IMSoP – 2016-08-05T15:07:42.587

@JonHanna I couldn't give a tinker's cuss whether grocers or groceries are involved - and I am not a tinker :-) If you want a good laugh, google for the Association for the Abolition of the Aberrant Apostrophe. I remember reading it when it was first published – Mawg says reinstate Monica – 2016-08-06T08:48:50.040

@CompuChip: correct me if I'm wrong, but isn't the Dutch apostrophe used to avoid changing the sound of the vowel in those cases? e.g. menus (short) v. menu's (longer). But if the vowel isn't changed by the s the apostrophe isn't used. (I'm sort-of learning Dutch) – LMS – 2016-08-06T09:34:06.843

1@LMS Yes, you are right, although I guess most words ending in a consonant have a plural ending in -en. And to make it complicated, some possessives take an apostrophe when the noun ends in an -s, e.g. "Peters boek", but "Jess' boek". – CompuChip – 2016-08-06T10:17:30.750

@Mawg, but "Grocer's apostrophe" only applies to incorrect use of apostrophes with plurals, not correct, if somewhat old-fashioned use, as per here. – Jon Hanna – 2016-08-06T14:04:07.013

IS that correct? Methinks not. Certainly not on this side of the pond – Mawg says reinstate Monica – 2016-08-07T11:16:59.987

@CompuChip, not only to make it complicated I think, but also to indicate a possessive, isn't it? Did I understand correctly - in cases like baby's and menu's, an apostrophe both makes plural noun and prolongs sound? – aryndin – 2016-08-08T08:18:09.863



It's one way of showing plurals that is used with acronyms.

It's widely-used, but whether it is correct is the subject of debate. It may be best to avoid its use in formal or professional documents. Generally, CPUs will always be considered valid, while CPU's may or may not be (this applies to other acronyms).

You may find these resources interesting:


Posted 2016-08-02T20:12:06.407

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13Technically, CPU isn't an acronym ;) – Catija – 2016-08-02T20:21:51.980

20@Catija: I'm calling "common usage" on acronym vs initialism :) – LMS – 2016-08-02T20:23:01.830

3You forgot to mention that anyone who thinks "CPU's" is a plural (rather than a genitive) is just plain wrong. :-P – Wildcard – 2016-08-02T23:04:50.123

13@Catija CPU isn't an acronym? It doesn't stand for "central processing unit"? That's what I learned some 30-odd years ago... – Doktor J – 2016-08-03T05:53:48.520

25@DoktorJ Technically the term acronym refers to initialisms that are pronounced as a word. Examples include NASA or scuba. If you say the letters individually, it is not an acronym. – Catija – 2016-08-03T06:06:47.697

@Catija so than TLA is not an acronym? – Davor – 2016-08-03T06:19:39.337

@Davor if you say "tee-el-ay" I guess not – Pierre Arlaud – 2016-08-03T07:41:02.423

1"whether it is correct is the subject of debate" - no it is not. This is gramatically wrong and there can be no debate about that – Mawg says reinstate Monica – 2016-08-03T08:39:18.333

4@DoktorJ: CPU is an acronym only if you pronounce it as chapu or kahpu. If you pronounce it as see pea you then it's an abbreviation, not an acronym. – slebetman – 2016-08-03T08:46:44.637

4@Mawg: style guides are inconsistent in allowing or prohibiting use of an apostrophe. See choster's answer, for example. – LMS – 2016-08-03T09:14:16.473

1I gather this is popular with things like "OS's" as OSs" looks pretty odd. – Tim – 2016-08-03T09:38:52.727

5@Tim: you can go for OSes if you don't like OSs, treating the former as a standard production for plurals of words ending -s. – Steve Jessop – 2016-08-03T09:45:59.983

19Blind prescriptivism makes me so frustrated! :P You cannot say "this is wrong" and "technically it means this" with language, it just doesn't work that way. You can say "according to X, it means this", or "based on logic Y it should be this", but there is no "perfect English" that exists somewhere that we are all trying to achieve. If 50% of the world said that "All TLA's are acronyms" is a valid and true English sentence, and the other 50% called it "wrong", there is no authority with the power to judge between them. – IMSoP – 2016-08-03T13:42:29.170

3@IMSoP Congratulations, you are one of the few people who seems to understand how language works. – Kik – 2016-08-03T14:18:43.110

@Kik - not exactly. What you two are talking about is all fine for spoken language, but prescriptivism is perfectly fine for written language, especially when the subject is something like an apostrophe which isn't even pronounced per se. – Davor – 2016-08-03T15:24:42.810

9@Davor I disagree. The rules for written language are just as arbitrary, and all that matters is that meaning is conveyed. If enough people use punctuation and understand that use, then it is perfectly valid. The idea of strict adherence to all these rules doesn't account for the fact that language and it's uses evolve. What is the "rule" today, will be archaic and not understood 200 years from now. – Kik – 2016-08-03T15:37:19.133

2@Davor The distinction isn't between written languages and spoken languages, it's between languages with formally codified rules (such as French and C++) and those without. English does not have an authoritative set of rules. – Kyle Strand – 2016-08-03T15:55:51.733

2@KyleStrand French has codified rules? I've never heard of that. Did the government define their language? – Cort Ammon – 2016-08-03T17:06:27.553


@CortAmmon Not originally, but they've established a committee with official authority over the language. There are apparently similar governing bodies for some other languages (notably not including English except in simplified forms such as Simplified Technical English).

– Kyle Strand – 2016-08-03T17:13:29.750

4@IMSoP I can't say that? Sounds dangerously prescriptivist. – hobbs – 2016-08-03T17:46:12.233

I thought someone might pick me up on the "can't" :P As for written vs spoken, French vs English, etc, all red herrings as far as I'm concerned. Any standardisation of a natural language comes after the language has naturally developed, and alongside it continuing to develop. The Académie française is certainly an authority on the French language, but users of French can and do disagree with it, and they are still speaking French. There'd be a stronger case for "it's wrong" being meaningful with French, but it still wouldn't rule out it also being "the subject of debate". – IMSoP – 2016-08-03T21:28:33.710

4What about MS-DOS? Is that an acronym or initialism? – rustyx – 2016-08-04T20:56:34.733

@IMSoP, those are good points—for widespread use. Indeed, the rules for language are all after the fact, as the important thing is that you communicate and that you are understood. However, communication is impossible without agreement. I can use words (and punctuation) to mean whatever I want them to mean, but if I am too far out of agreement with my audience, I simply won't communicate. Otherwise there would be no reason to teach grammar, spelling, and punctuation in schools, since "none of the rules are valid anyway." – Wildcard – 2016-08-10T01:08:02.150

My favorite definition of grammar: "The way words are organized into speech and writings so as to convey exact thoughts, ideas and meanings among people." It is essentially a system of agreements as to the relationship of words to bring about meaningful communication.

– Wildcard – 2016-08-10T01:12:38.003


Punctuation is a matter of style. Here, 's is almost certainly used to pluralize the initialism CPU, but whether this is appropriate depends on which style manual you, your editor, or your organization follows.

The New York Times stylebook, which is derived in large measure from Associated Press style, has this to say about plural abbreviations:

Use apostrophes for plurals of abbreviations that have capital letters and periods: M.D.’s, C.P.A.’s. Also use apostrophes for plurals formed from single letters: He received A’s and B’s on his report card. Mind your p’s and q’s.

But do not use apostrophes for plurals of abbreviations without periods, or for plurals formed from figures: TVs, PCs, DVDs; 1990s, 747s, size 7s.

In contrast, APA Style fully rejects any use of apostrophes to indicate plurals:

Just as with numbers, don’t include an apostrophe when pluralizing abbreviations. For example, when pluralizing an acronym, such as “CV” for “curriculum vitae,” all you need to do is add an s to the end, as in “CVs.” This rule also applies to standalone letters, as in “The students all received As.” For abbreviations that end with a period, such as “Ed.” to indicate an editor in a reference list entry, add an s before the period, as in “Eds.” When pluralizing an italicized abbreviation, remember not to italicize the s, as in “ps.” Just don’t add an apostrophe.

The Oxford Guide to Style (2002 edition of New Hart's Rules) offers similar guidance:

Do not use the apostrophe when creating plurals. This includes names, abbreviations (with or without fall points), numbers, and words not usually used as nouns: the Joneses · several Hail Marys … · B.Litt.s · QCs … · the three Rs … · sixes and sevens

The Chicago Manual of Style guidance states

Capital letters used as words, numerals used as nouns, and abbreviations usually form the plural by adding s. To aid comprehension, lowercase letters form the plural with an apostrophe and an s.


Posted 2016-08-02T20:12:06.407

Reputation: 16 753

4Wow! APA really wants "What's with all the maybes?" and "Your penmanship is good except for your is and ss."? Crazy. – David Schwartz – 2016-08-03T07:19:20.013

9@DavidSchwartz: Personally I'm happy with your first example: if "maybe" is a noun that can be pluralised, then the plural is "maybes". But it could be fixed as "What's with all the "maybe"s?" The latter could be semi-fixed as "Is and Ss", or at a risk of sounding archaic, as "ies and esses". This is what happens when you make a prescriptive rule, they've painted themselves into some unpleasant corners. – Steve Jessop – 2016-08-03T09:50:32.613

3You should potentially add the Oxford Guide to Style as a UK English reference (showing that this isn't just an American choice to not use an apostrophe here): "Most abbreviations form the plural by adding -s: VIPs, MCs, SOSs" – Jules – 2016-08-03T11:00:19.410

1@SteveJessop Quoting "maybe" changes the meaning. With the quotes, it's asking about uses of the word "maybe". Without the quotes, it's asking about indefinite responses, regardless of what word was used for them. Also, changing to "Is" changes the meaning. A capital "I" has a different meaning from a lower case "i" in the middle of a sentence. For example, if someone uses the concept of self a lot, you could call that "Is", but not "is" or "i's". – David Schwartz – 2016-08-03T11:10:55.827

1@DavidSchwartz Following their style guide it would be "Your penmanship is good except for your is and ss." – CJ Dennis – 2016-08-03T13:29:45.337

@CJDennis Exactly. And maybes. [italics on everything except the "s"] Isn't this completely standard when citing words, etc.? – underscore_d – 2016-08-03T14:01:12.587

@Jules Good suggestion; added. I did not have my copy with me when I wrote the answer. – choster – 2016-08-03T14:07:00.300

3You provided references to four separate style guides, but none of them support the assertion that 's is acceptable in this case. The NY Times and Chicago style guides advocate its use with abbreviations that include periods, but CPU is not such an abbreviation, and their stance is that it should be "CPUs." I'm not saying there that it isn't a valid stylistic choice, but you should probably find an example to prove that it is before making the claim. – bcrist – 2016-08-04T01:56:09.337

@bcrist The entire point of my answer is that punctuation is a matter of style. This is a prime example: four style guides agree that CPUs is the acceptable form, yet differ wildly on very slight variations thereof. Authors need to understand that the final arbiter for such matters is their editor , and what a bunch of anonymous Internet posts referencing what some or other outside authority has to say about what is correct is of distinctly secondary consideration. – choster – 2016-08-04T16:11:41.743


The form CPUs is increasingly not the more widely accepted and may completely replace that use of apostrophe, but not so long ago CPU's was the more widely accepted. I go into more detail on this on an ELU question at http://english.stackexchange.com/a/104235/15770

– Jon Hanna – 2016-08-05T10:33:20.230

@JonHanna That is an amazing answer. You should link to it more prominently, as a comment on the question, or even an answer picking out a couple of key sentences and linking for background. – IMSoP – 2016-08-05T11:13:05.840

@IMSoP I should also correct the typos ;) On phone right now so that's not too handy, feel free to produce an answer here based on linked relevant excerpts if you want to. – Jon Hanna – 2016-08-05T14:37:47.473


There's a lot of argument about proper pluralization of acronyms and initialisms.

Both using and not using apostrophes is an acceptable method of pluralization (depending on what resource you use), so it's a matter of case-by-case interpretation to determine whether it's possessive or plural.

There's no way to interpret the sentence you have in your image as a possessive statement, though, so it is clearly being used as a plural form of CPU.


Posted 2016-08-02T20:12:06.407

Reputation: 25 211


Because not using an apostrophe often looks ridiculous, it cannot be universally prohibited. Since it's not universally prohibited, it is sometimes allowed. For "CPU", some people prefer "CPU's" for the plural but most prefer "CPUs".

To see why you sometimes have to use an apostrophe to indicate a plural, try removing the apostrophes from the plurals in bold below.

"Your penmanship is good overall, but your S's and I's need more work."


"What's with all the maybe's?"

David Schwartz

Posted 2016-08-02T20:12:06.407

Reputation: 1 230

3What is it with all the maybes? In other words, would you care to explain, why "maybe" is substantially different from any other noun placed in that position? If it's exactly because it's not a noun, what's your take on "do(')s and don'ts"? – LLlAMnYP – 2016-08-03T08:54:26.193

It's because if you write "maybes", it reads like it should be pronounced "mayb-z". See the Chicago Manual of Style. – David Schwartz – 2016-08-03T09:42:47.147

This makes even less sense now. English is notorious for "this pronounciation here, that pronounciation there" and suddenly it's accomodating ease of understanding. And Chicago contradicts you. -- oh wait, it's dos.

– LLlAMnYP – 2016-08-03T09:53:40.880

2"it reads like it should be pronounced" - This valiant effort notwithstanding, the ship has sailed on words in English that don't read how they're pronounced ;-) – Steve Jessop – 2016-08-03T09:54:07.303

3@SteveJessop make no mistake, "maybes" should be pronounced may-bees and that's exactly how it reads :-) – LLlAMnYP – 2016-08-03T09:55:13.427

@LLlAMnYP: sure that's how I read it too until David pointed out that it could be interpreted differently. But if he doesn't like the way a word looks (to him) compared with how it's pronounced, then IMO he's free to avoid it! – Steve Jessop – 2016-08-03T09:55:45.857

@Steve googling suggests, there's no such thing as "mayb-z" though. – LLlAMnYP – 2016-08-03T09:59:31.613

@LLlAMnYP That would be the source of confusion. There's no such thing as "ls" either, so if you are talking about more than one l, using "ls" confuses people. Yes, rationally it can only be a plural l, just as "maybes" can only be a plural maybe. But it's rude to force people to reason out what you mean when the language has a way for you to easily make it clear. – David Schwartz – 2016-08-03T11:13:04.497

1The way to make it clear is to use the tool that's traditionally used when referring to a part of some other text: quotes. What's with all the "maybe"s? and your "S"s and "I"s need more work. – Blorgbeard is out – 2016-08-03T20:36:41.817

@Blorgbeard You're not making it clear, you're making it mean something completely different. When you put "maybe" in quotes, it means the word "maybe" rather than the concept of an uncertain response. I was talking about vague commitment however expressed, not use of the word "maybe". Similarly, there is a distinction between s, the letter s, and "S", something having the shape of the letter s. By using quotes around "s", you changed my meaning to refer exclusively to the letter. Perhaps I meant all things shaped like an s. – David Schwartz – 2016-08-03T20:43:56.087

1Well, I didn't get that impression from your text with apostrophes, so it seems they're not really doing the job either.. And I doubt you were referring to general s-shaped things, considering "penmanship". Can you come up with an example that doesn't involve a noun that's not usually a noun? – Blorgbeard is out – 2016-08-03T21:04:41.057


Whatever the New York Times may say about it, why should one use the apostrophe as an additional sign for plural? 's is indicative of the Saxon genitive.

My best advice is: keep 's for the Saxon genitive and regard other usages as a common mistake (yes: mistake). In that case: What CPUs will it run on?

Incidentally, the quoted piece of reference is stale —PowerPC was outphased more than a decennium ago.

Brice C.

Posted 2016-08-02T20:12:06.407

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