When you are finishing a sentence with a sir name but it is plural Do you use ' or 's at the end?
A surname is a proper noun. The possessive forms for proper nouns follow the same rules as common nouns:Possessives are formed by adding an apostrophe -s ('s) to the end of the word, or just an apostrophe (') to then end of plural nouns that already end with -s. Examples:Mr. Brown's house, or the plural: the Browns' house.Ms. Bass's house, or the plural: the Basses' house.Mr. Cruz's house, or the plural: the Cruzes' house.Since surnames do not have irregular plural forms, a plural surname will always end with an -s; the plural possessive form will always end with -'s.