To pluralize a last name, generally add an "s" to the end of the name without changing the spelling of the name. If you are talking about a whole family, such as the Smith family, call them "the Smiths."
Names that end in sh, ch, s, or z add -es to form the plural: the Marshes; the Binches; the Joneses; the Katzes
You would pluralize the last name Chin by adding an S to the end so it becomes Chins. For example, collectively as a family unit, Mr and Mrs Chin could be called The Chins.
There is no specific rule in English for forming the plural of a noun that ends with an "o". Common nouns that end with "o" add either an "s" or an "es" to the end of the word.A proper noun ending with "o" can form the plural with either ending: Tisos or Tisoes.A person with the name "Tiso" may have a preference of their own.
To pluralize a last name ending in "s," simply add an apostrophe after the "s" without adding an additional "s." For example, the Smiths' house is correct for the plural possessive form of the Smith family.
Add an apostrophe - Russ'
Cylinders.
McDonald's
boats
cobwebs
Martinez's
You wouldn't pluralize "processing", but you would pluralize "process" making more than one process "processes".
Handkerchiefs is correct.
Fournesses is the plural of Fourness