Help me with my apostrophe use!

[RedCardigan]

So if you were making sign that said “Summer at the X’s” I’m happy that if the family name was Smith, then it would be “Summer at the Smith’s”.
But what if the surname ends in an “S” like Jones? Would it be “Summer at the Jones’s” or “Summer at the Jones’ “ or something else? Google is not helping!

Yes, if you're talking about the Smith family (a plural) the apostrophe goes after the s:

John Smith's house (singular)
The Smiths' house (plural) meaning the Smith family's house.

...I'm now feeling slightly sorry for the single blacksmith who lives alone at the Smith's house 😁

The sign example is a good one, because I think that all three Jones’s, Jones’ or Joneses can be correct depending on context, and in the example of the sign any of the three contexts can apply

Start simple…

The boy’s toy (belonging to one boy)
The boys’ toy (belonging to many boys)

Summer at the boy’s (at a place belonging to one boy)
Summer at the boys’ (at a place belonging to many boys)

Apply the same rule to family names with no S

The Hardy’s car (belonging to one Hardy, technically correct but stylistically weird and most likely used with a nickname)
The Hardys’ car (belonging to many Hardys)

Summer at the Hardy’s (at a place belonging to one Hardy family)
Summer at the Hardys’ (at a place belonging to many individual Hardys)

Where the name ends in S the rule is the same if you ignore the third option…

James’s toy (belonging to one James)
James’ toy (belonging to many boys named James e.g. There were three boys called James in the class, and all the James’ coats were mixed up.)

Summer at the Jones’s (at a place belonging to one Jones family)
Summer at the Jones’ (at a place belonging to many individual Joness)

Where the noun ends in S there is a third alternative which is not to use the contraction, the problem being that you then have to infer from context whether there is a plural

Jameses toy - could mean one or many James, but you would normally infer to be singular.
Summer at the Joneses - could mean one or many Jones and would usually infer from context it’s plural.

So back to the sign

Summer at the Jones’s (at a place belonging to one Jones - in this case the singular Jones family)
Summer at the Jones’ (at a place belonging to many Joneses - the multiple members of the Jones family)
Summer at the Joneses (could mean one or many Jones either the singular Jones family or it’s plural individual members)

So any of the three can be correct depending on whether the you intend Jones to be single or plural, and in this case you can legitimately refer to the individuals named Jones as a single family or plural individuals without changing the meaning of the sign.

So the sign is a nightmare.

Summer at the Jones's
Or
Summer at the Jones'

Both are correct - but the 2nd looks better

No this is wrong - it is possessive not plural in this case

Yes, that's right.

The seller that I buy from has it “Summer at the Smith’s” so I’ve been giving people grammatically incorrect signs? poo

Mr Smith
Mr & Mrs Smith
The Smith Family
The Smiths.

We went to the Smiths’ this summer.
We went for summer at the Smiths’.

(Smith is very odd to type over and over)

Sorry but some of these examples are wrong.

"Where the noun ends in S there is a third alternative which is not to use the contraction, the problem being that you then have to infer from context whether there is a plural

Jameses toy - could mean one or many James, but you would normally infer to be singular.
Summer at the Joneses - could mean one or many Jones and would usually infer from context it’s plural."

This is incorrect. Apostrophes are for contractions or possession. You can dispense with a contraction apostrophe by writing the word out in full, e.g. wouldn't becomes would not. You cannot dispense with a possessive apostrophe. Jameses toy is wrong, as is summer at the Joneses. They both need a possessive apostrophe.

Also you wouldn't write Summer at the Jones' as you pronounce this "Joneziz" not "Jones" so you need to add the extra s to make it Jones's.

You wouldn't add the extra s to Smiths' as you pronounce it "Smiths" not "Smithziz".

If you think of a surname like Brown you’d say I’m meeting the Browns later. Just a plural.
for Jones you’d say I’m meeting the Joneses later.
I’m going to the Browns’ house - you add an apostrophe to show that the house belongs to more than one brown.
Following the pattern, it would be -I’m going to the Joneses’ house if you are referring to the house of more than one Jones.
Jones’s would be for- I’m going to Miss Jones’s (singular) house.