I’ve read conflicting rules on the use of apostrophes so I need a punctuation guru to set me straight. Now I know that you never use one when pluralizing a word. And I know that you do use one in contractions (ie, can’t). But what about when showing possession? I thought “The cat licked it’s fur” was right. Or with an name, “I’m going to Johnny’s house”. Or what about names that end in “S”? It is, “I’m going to Jesus’ house” or “I’m going to Jesus’s house”? Help!
I’m hardly an English guru, but I was always taught that names ending in “S” should have the apostrophe placed after the “S” with no additional “S’s” added (ie. Jesus’ house would be correct).
You use an apostrophe to show possession for nouns. Not for pronouns. So, cat becomes cat’s and authors becomes authors’. However, he becomes his, we becomes our, and it becomes its.
I thought “The cat licked it’s fur” was right.
Sorry, that’s not right. “It” is a personal pronoun, and personal pronouns have possessive forms that do NOT use apostrophes. Possessive personal pronouns include mine, ours, yours, his, hers, its, theirs, and whose.
…what about names that end in “S”? It is, “I’m going to Jesus’ house” or “I’m going to Jesus’s house”?
“I’m going to Jesus’ house,” is correct, as is “I’m going to Tom Jones’ house.”
“Its” as posessive is the one that used to get me. Just remember that if it could be hers or his, it should be its, not it’s.
There’s another big debate about using apostrophes to pluralize numbers. I tend to use them on numbers when just adding an S would create a contraction and not otherwise.
IOW:
“He rolled five sevens.” or “He rolled five 7s.” Since “7” is “seven”, “7s” is “sevens” and not a contraction.
“100 iterations of rand(100) gave three 70’s.” or “100 iterations of rand(100) gave three seventies.” Since “70” is “seventy”, “70s” would be “seventys”, which isn’t a word, thus “70’s” for the contraction “sevent’s”
That is, by far, the nuttiest rule in the written english language that I use. I’m pretty sure that no one else does, so you can probably ignore it and go all or nothing with pluralizing numbers.
Then there’s creating plural acronyms…
Yes, technically, one should never use an apostrophe when pluralizing any noun. Therefore, for instance, VCR’s is incorrect, and VCRs is correct. The term S’s in Phlint’s post is also technically wrong. However, without the apostrophes, these words often become difficult to read:
I don’t like this font; the us and the as look too similar.
Well…
By the letter of the grammarian’s law, it should indeed be “s” apostrophe “s” for a singular ending with “s”, but because of common usage, the final “s” has become less and less used and many grammarians predict that even the letter of the law will change and that final “s” will go the way of the dodo bird (despite our continuing to say it when we speak. Listen to yourself when you say it. You do in fact say, “Tom Jones’s” and “Jesus’s house”). Thus it is acceptable to write “Jesus’” and “Tom Jones’ house”.
The grammar instructor (from Northwestern for what it’s worth) I asked about this said that the dropping of the final “s” following the singular “s” may well be able to be blamed on newspaper style. For almost a century now, both AP and UPI press books have advocated just the apostrophe as opposed to traditional grammar books rules that said to add it.
We’ve been taught not to have naked apostrophes. Always clothe your apostophes! So an “s” should follow the apostrophe-“s”.
“Seventys” isn’t a word, but “seventies” is. And “70’s” is NOT a contraction. How plurals are expressed for numerals varies from publication to publication - some use the 's and some just use an s (we use the s, now).
And as for “it’s” - just remember that that is a contraction, of “it is”, and not a possessive of anything.
One more note: it IS correct to use an apostrophe in the pluralization of individual letters.
“If the M’s and the T’s of the world don’t stop sponsoring Sesame Street, we’ll be inundated with More Tripe!”
Wow, people learned lots of different apostrophe rules here! For some reason, my high school English teacher told me that the only two words in the English language that are ___s’s instead of ___s’ are (wait for it) Jesus and Moses. And my school wasn’t religious or anything. I’m officially perplexed, although that rule never did make a whole lot of sense to me.
I’ve always heard that if the word ends in ‘s’ you just add an apostrophe, making “Going to Tom Jones’ house” correct. Just recently I came across a new twist here at work: What do you do when the word ends in two, uh, hm, esses? What I learned was that you add the apostrophe and another ‘s.’ Like “I’m going to Frank Mass’s house.” Seems odd, but I’ve been told that it’s correct.
The problem is that the use of apostrophes is partly covered by rules (it’s vs. its is a rule) and partly by styles (Jones’ vs. Jones’s) is a style.
Teachers all too often don’t even try to make the distinction, for undestandable reasons. But that leads to conflict in the adult world when one teacher’s style bumps up against another teacher’s style.
There are style manuals to use professionally, but individuals just have to fall back upon their own good sense and try to keep consistent whatever style they decide on.
But it’s going to be a jumble no matter what.
The third edition of Strunk & White, which was my grammar bible, calls for the second apostrophe: Jesus’s miracles, Jim Jones’s psychoses.
I do not have my Chicago or Fowler’s here.
Exapno Mapcase is correct about whether or not one should add apostrophe-s or just the apostrophe to make a noun ending in s possessive: It depends on who you ask. I forget which one is which, exactly, but I know that the major newspaper style guides differ on this question. Some say just add the apostrophe (e.g., Bridget Jones’ Diary) while others advocate the apostrophe-s (Bridget Jones’s Diary). There’s no hard-and-fast rule.
Speaking for myself, I add the apostrophe-s. I see the lone apostrophe as a sort of speed bump, a typographical convention that doesn’t match the way we speak (we say, out loud, “Bridget Joneses Diary”) and that adds a microsecond of interpretation to the reading experience.
That being said, it’s is always a contraction for “it is,” and its is always the possessive form of “it.” No exceptions, and no room for bastardized forms like its’.
What about possesive forms of nouns that end in the letter z? I remember learning to treat them as nouns that end in s. I’d type: Someone needs to do something about Gaz’ anger control issues., for example.
- My last name is Jones, so I live with this sort of thing.
You absolutely SHOULD put the S after the apostrophe when pluralizing a proper noun that ends with S. Jones’ is wrong; newspapers may do it to save space, but Jones’ is not a word in any language. “Jones’s” is correct. Trust me, I should know. 
Nouns that end in S or Z do not change the rules of possessives. It’s Jones’s, Gaz’s, moss’s, Lycos’s, floss’s.
TheWrongGirl, your high school English teacher was a twit.
- When it comes to the possessive of “it,” just remember that PRONOUNS DON’T USE APOSTROPHES!
Yours
Hers
His
My/mine
Theirs
Its
All possessive pronouns and no apostrophes.
It’s been many years since I took English, but it’s is not always a contraction for “it is”. 
Unless you mean that it’s is sometimes a contracted form of “it has” then you’re going to have to provide examples.
Possibly a bit strong, but honestly, most high school English teachers have never taken a college level grammar course. I would bet that less then 15 percent have. It probably is even a lower percentage than that. In some states you can teach high school English with as few as 10 hours of college English courses. It is no wonder that TheWrongGirl’s English instructor blew this one.
Exapno Mapcase,
Yeah, I meant “it’s” can be a contraction for “it has”. If you want an example, look at my previous post; it’s got an example. So does this post.