Why does a plural possessive noun end in 's?

[chai]

I tried to teach dd about plural possessives today and she had a minor breakdown because it doesn't make sense. I tried to tell her that she just needs to learn the rule--it really isn't that difficult to follow, but she wants to the know the reason for the rule.

I was able to find the reason for the singular possessive with an apostrophe. (In case you want to know: In Old English, the plural of man was mannes. Then the apostrophe was used to replace the ne.) I was not able to find a similar reason for the plural possessive. Does anyone know the answer?

[Deece in MN]

Well, plural possessive nouns don't end in 's, they just have an ' added to the end because there is already and s on the end (for most plural nouns anyway).
The ' is to show that you are talking about possession not just the plural of the noun.

Is this what you are asking, or am I missing something? :)

[PariSarah]

I was able to find the reason for the singular possessive with an apostrophe. (In case you want to know: In Old English, the plural of man was mannes. Then the apostrophe was used to replace the ne.) I was not able to find a similar reason for the plural possessive. Does anyone know the answer?

You could tell her that it was by "false analogy." People got used to the association between apostrophes and possessives, so they started using it where it didn't really belong just because it would be helpful. And it stuck because it was so helpful. There are lots of other examples of spelling rules changing or being established through false analogy, none of which I can come up with at the moment.

And I have no idea what the real reason is, but doesn't this sound convincing?

[Ellie]

It is what it is. She might just have to break down over it for awhile until she gets used to the idea. Many things that we say and do are simply because it is what it is.

[Kathy in MD]

Well, plural possessive nouns don't end in 's, they just have an ' added to the end because there is already and s on the end (for most plural nouns anyway).
The ' is to show that you are talking about possession not just the plural of the noun.

Is this what you are asking, or am I missing something? :)

nt

[chai]

I did make dd continue with the exercises in spite of the meltdown. But I also promised to try to find the answer. She really needs to understand the logic behind things. When an answer or rule isn't logical, she gets upset because it confuses her. She has always learned that an apostrophe replaces one or more letters; in the case of a plural noun ending in "s", this isn't really true. I'm going to try the argument that it replaces a second "s", but I don't think that she'll buy it. (Then she'll want to know why it doesn't have two apostrophes.) I'll try the false analogy too, but that may open another whole can of worms.

On the other hand, bribery can work well. This afternoon, after school was over, she asked to use my computer. When I told her that I was researching her question, she was adamamant that she didn't need the answer any more. I guess computer time is more important than understanding plural possessives! :D