s apostrophe, genitive s

How to spell words with apostrophes correctly

We always add -s with an apostrophe in English.

• Ronny's brother

1. Singular

Add 's to the noun.

• Mandy's brother John plays football.
• My teacher's name is ...

2. Plural

Add the apostrophe ' to regular plural forms:

• The girls' room is very nice.
• The Smiths' car is black.

Add 's to irregular plural forms:

• The children's books are over there.
• Men's clothes are on the third floor.

If there are multiple nouns, add 's only to the last noun:

• Peter and John's mother is a teacher.

If there are multiple nouns that refer to one person/thing – add 's to the last noun.

• Peter and John's mother is a teacher.

If there are multiple nouns that refer to more persons/things – add 's to both nouns.

• Susan's and Steve's bags are black.

3. Singular names ending in -s

Although it is not considered to be good English, you may add only the apostrophe words ending on unpronounced -s

• Charles's dog – Charles' dog
• Illinois's capital – Illinois' capital

Words ending in -x and -z follow the same rules.

• Felix's car – Felix' car

But there are situations where only 's is the best choice to make the meaning clear.

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