Possessive 's VS is 's

I'm a teacher and every time that it comes to teach possessive 's VS is 's, students get confused and can't distinguish them.

For example:

Rita's brother's name's John.

They can't understand which is for possessive and which is for be form, "is". Can you help me?

• possible duplicate of How does the possessive apostrophe work in "it's"? Commented May 19, 2015 at 0:17
• The question Nathan linked is interesting. Do you think the kids understand English well enough to realize that, "Rita is brother's name's John" and "Rita's brother is name's John" are wrong, while "Rita's brother's name is John" is correct? Commented May 19, 2015 at 0:49
• Don't forget 's can also be has!
– user230
Commented May 19, 2015 at 3:03
• @user3169 Their is no unabbreviated form of possessive 's'. Commented May 19, 2015 at 9:37
• @Araucaria I meant writing it without the 's, but it came out wrong. I'll correct that and write a new comment. Commented May 19, 2015 at 17:50

The second form (is 's) is correct only when the 's spelled out is correct.

Rita's brother's name's John.

This can only mean

Rita's brother's name is John.

because none of the following are correct:

*Rita is brother's name's John.

*Rita's brother is name's John.

*Rita's brother is name is John

Etc.

Spell each each occasion of the 's and see if it is grammatical. If I am right, there are 9 possibilities here (3 x 3 = 9) and the only correct one is the first one.

• Actually, it’s not nine, but eight. You have three contract-or-not questions. So for each of the pair of options for Rita you have a pair of options for brother, and for each of those, a pair of options for name. And 2 cubed is 8. (This is what you get for allowing mathematicians onto ELL.) Commented Nov 17, 2023 at 12:11

It's amazing how complicated this can become. I think we native speakers would usually try to avoid using more two 's in any one sentence. You can usually think of some way of avoiding their use by rephrasing. It's also important I think to make it clear when you're teaching that he is = he's is an aspect of spoken English and indicates informality. I don't think it is ever required, just an option. On the other hand my father's hand is much better than the "the hand of my father" across all situations and not using the 's for possession can be an error. As a teacher I try to keep clear of the possible complications, especially with children (there are plenty more).

• I don't think it's true that we avoid using more than two of these: I think it's just that multiple possessives (like "my boss's daughter's boyfriend") are a bit rare by their nature. Commented Dec 5, 2016 at 19:46