Usage of 's: Mr Pike is a teacher of Jack/Jack's.

[Nessie]

Hi,
Please tell me which of these two sentences is more correct/common/popularly used:

Mr Pike is a teacher of Jack
or
Mr Pike is a teacher of Jack's

Also:
She's a friend of my sister
or
She's a friend of my sister's

Many thanks
Nessie
_________________
... something we never have again, I know... I guess I really really know..

Sorry seems to be the hardest word...

[Rajin]

Mr. Pike is a teacher of Jack's or else Mr. Pike is Jack's teacher.

I think in the second sentence you would use "She's a friend of my sister" simply because sister's in that place could get confused for sisters and would mean the whole family instead of just one and thus might prove confusing. Again, "She's my sister's friend." is best.

[Manal]

Mr. Pike is a teacher of Jack's.

Why not Mr. Pike is a teacher of Jack.

Is the first sentence idiomatic?

[MrPedantic]

Hello Nessie,

1. Mr Pike is a teacher of Jack

— this isn't quite the same as #2 in meaning; it would be a quite unusual way of saying "Mr Pike is Jack's teacher".

2. Mr Pike is a teacher of Jack's

— this means "Mr Pike is one of Jack's teachers".

3. She's a friend of my sister
4. She's a friend of my sister's

— both are fine; the "double genitive" in #4 may seem puzzling, but is perfectly idiomatic.

For me, #3 suggests the viewpoint "friend → sister", while #4 suggests the viewpoint "sister → one friend among several"; but I suspect this would not be shared by all other members.

Best wishes,

MrP

[Molly]

[Yankee]

[Molly]

[Nessie]

Thanks you all for your ideas

Actually from what I am taught here, the "double genitive" is COMPULSORY in these cases, which means that in formal English we can only say these:

He's a friend of mine
She's a friend of my sister's
Mr Pike is a teacher of Jack's

Therefore I just want to see about ideas of native teachers whether this rule is absolute.
Many thanks in advance
Nessie

P.S:
Hi MrP,
In your last post, did you mean that #1 is also ACCEPTABLE in British English? And in this case it is not completely the same as #2 because #2 refers to the possibility that Mr Pike is ONE OF Jack's teachers while # doesn't?
Many thanks.
_________________
... something we never have again, I know... I guess I really really know..

Sorry seems to be the hardest word...

[Molly]

A: Who is actually the teacher of Susan & Jack? Remind me.

B: I've told you many times, Mr Pike is a teacher of Jack and Ms Molly is a teacher of Susan.

.............

So, according to Amy's reading, "He is the teacher of George" means "He's teaches the subject called George".

[Yankee]

.
Do you purposely try to mislead ESL students, "Molly"?
.

[Molly]

[Molly]

[MrPedantic]

[Molly]

[Molly]

What would you choose here and why?

Excuse me, I'd like to talk to a teacher of Jack.
Excuse me, I'd like to talk to a teacher of Jack's.