Apostrophe 's or s'

The plurals of last names are just like the plurals of most nouns. They typically get formed by adding -s. Except, that is, if the name already ends in s or z.

Then the plural is formed by adding -es.

the Smith clan → the Smiths

Jill and Sam Clarence → the Clarences

Mr. and Mrs. Jones → the Joneses

the Fernandez family → the Fernandezes

Unlike regular nouns that end in y, names that end in y are also made plural by adding -s:

the Kennedy clan → the Kennedys

the Daley family → the Daleys

Possession And Names

If you want to talk about something that belongs to more than one member of a family, you start with the plural form and add an apostrophe to show possession:

the Smiths' car

a party at the Fernandezes' house

the Daleys' driveway

If you want to talk about something that belongs to a single person being identified by last name, you follow the usual -'s rule for most names:

the car that belongs to Smith → Smith's car

For names that end i

apostrophe when someones name ends in s

apostrophe s after company name ending in s