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:
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:
Intuitively, we try to label all uses of the genitive 's as possession, but semantically it just doesn't work. It's true that 's is prototypically used for possession, but it has all sorts of other uses. For example, in an hour's delay, the genitive phrase indicates how long the delay is. Clearly it doesn't indicate that the hour owns a delay. (What ...
We don't have to. It's equally correct to say
She is at the dentist now.
(you can interpret "the dentist" as a synecdoche in which the person stands in for the place) or
She is at the dentist's now.
(an elliptical way of saying "She is at the dentist's office now*).
Which you choose probably depends on what you hear more.
Both express possession, of course.
We use 's with singular nouns. For example, "my son's toys" will be "the toys that belong to my son".
We use only an apostrophe (') after plural nouns that end in -s: "my sons' toys" means that I have more than one son and these are their toys.
We use 's for possession with the other plural nouns. For example: "my ...
It's really just a stylistic choice, as per this related ELU question, but most style guides would suggest you shouldn't use the apostrophe, and these days, that's what most people do...
I should also point out that if the apostrophe is used, it can't represent "possession/association" unless followed by another noun. You can say I was last year's winner, ...
It is quite common for a company to be referred to by the possessive form of its proprietor's name, and to take that possessive as its trade name. For instance, my great-great-grandfather Morris Rich founded a department store which eventually became known as Rich's.
Compare Rick's in Casablanca, and our ordinary use of someone's name to refer to their ...
It depends how you think of it.
If your intent is, "an icon that belongs to 1990", then you should write "1990's icon".
If your intent is, "an icon that belongs to the decade of the 1990s", then you should write "1990s' icon".
But we also often use nouns as adjectives without using a possessive. Like, "this is an automobile part". It's not a possessive. ...
You need an apostrophe to mark a possessive case here. However, the possessive case doesn't refer to ownership in such examples, instead it refers to the meaning "is intended for":
A patient's guide to [X]
A student's guide to [X]
A teacher's guide to [X]
This means that this guide is intended for students, teachers or patients.
Example "The Hitchhiker's ...
The contraction of "is" in "it's" can only occur if the "is" is relatively unstressed, which cannot be the case when it is final in a sentence or clause. Consequently, contractions like "it's" and "I'm" never occur at the end - they are always expanded, so that some stress can go on the verb "is" or "am".
This is very noticeable when a lyricist ...
No. The rule is simple:
For regular plurals ending in s, the possessive suffix is '.
In all other cases, the suffix is 's.
Children is an irregular plural, not a regular one. Therefore, the suffix is 's, and the possessive form is children's. Your form *children's' is incorrect.
However, the other possessive forms are fine. Parents is a regular plural,...
"The Night Sisters" is a plural noun. Therefore the possessive form is "The Night Sisters'", adding just an apostrophe. The proper form of thre example sentence is
Mary tended John throughout the Night Sisters' passing.
Similarly with other plural nouns:
I greatly enjoyed the Bermuda Islands' sunny beaches.
"the Bermuda Islands" is a plural noun
So let's start with the singular 'brother-in-law', which is perfectly clear. If you have a single brother-in-law and he possesses something, this is written as:
My brother-in-law's cooking skills are excellent.
If you have more than one brother-in-law (no possession) you would write:
My brothers-in-law are all brunettes.
This is because when ...
If you use the S, it must be "A patient's guide", which implies that the guide is possessed by a specific patient, or "Patients' guide", which implies that the guide is for multiple patients. I would argue the latter is more grammatical, although the first seems more common. I think one could justify both. The first could be justified as being ...
Fluffy's answer is correct about the possessive usages, so I won't repeat those. However, it misses an important point.
Possession isn't the only use for 's; it can also be a contraction for is. For example: it's, how's, he's, she's, that's, etc. In standard English, s' is never a contraction*.
The double meaning of 's leads to one of the most common ...
There are no rules limiting the number of instances of such punctuation, and likewise there is no limit to the levels of possession that can be attributed to something. But as you observe, both the repetitive usage and the denseness of the nested genitive make it difficult to parse, and something to be avoided.
But we rarely ever trace more than about three ...
As is ever the case with style in English, there is no hard rule except to be consistent within the parameters of the style guide you are using. That said, I know the Chicago, MLA, and Associated Press manuals all say not to use the apostrophe to pluralize dates, contradicting your contradictory source regarding American usage.
The common explanation behind ...
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 ...
This is a matter of style. In an interesting 2010 blog post that touched on this topic, one writer quoted from the style guide of the New York Times:
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. ...
Monica is right - they're all possessives.
Possessives dont need to denote ownership. "Morgan's house" may mean the house he owns, rents, is building, has painted on a piece of paper, is designing as an architect, etc etc. "Morgan's book" could mean the book he wrote or is writing, bought and now owns, borrowed from the library, etc etc. In fact, in some ...
No, there is no rule in English that says you cannot have more than 3 apostrophes in a sentence or any such number. Just as there is no rule that says you cannot say "of" more than some number of times, or you cannot have more than so-many distinct clauses, etc etc. OF COURSE it is possible to write a sentence that obeys all the regular rules of grammar, but ...
The phrase [at] arms length (not on familiar or friendly terms; at a distance) is almost always used figuratively, so it doesn't really make much difference whether the apostrophe comes before or after s (as S.F. points out, if it comes after, you're referring to the length of two or more arms).
But in practice at the length of an arm is invariably what we ...
Adding the 's to make "dentist's" indicates the place owned by the dentist - in this case the dentist's surgery.
It is common to say that you are "at" a place - e.g. at the office or at the railway station. So "at the dentist's" is correct.
It is not common to say that you are "at" a person. "She is with the dentist now" would sound better.
They are both correct.
A book's cover is called a book cover
Book in book cover acts more like an adjective describing cover just as
these are saying what the cover is associated with. It is possible the usage of book's cover changed to book cover sometime in the past.
Though they both refer to ...
Merriam-Webster's Manual for Writers and Editors says:
No apostrophe is generally used today [1998. -p.a.s] with plural nouns that are more descriptive than possessive.
Examples they give are "steelworkers union", "managers meeting" and "singles bar". I think patients guide fits in that group nicely: After all, the patients indeed do not actually own it.
When the shop is named after the owner it is fairly common to use a possessive to describe it:
A butcher is a person. A butcher's (shop) is a place to buy meat.
A dry cleaner is a person who cleans clothes. A dry cleaner's is the shop where he works.
Now there is quite a lot of variation here. Some people will write and say
I'm going to the dry ...