Possessive 's/s'

In this lesson, you will learn how to use 's and s' to show possession with singular nouns, plural nouns, names ending in s, and compound nouns.

1. The Basic Idea

Use 's with a singular owner: one person, one animal, or one thing.
Example:

• “Maria's bag is on the table.”
• “Tom's jacket is on the couch.”

2. Core Rules: Singular and Plural Possession

Here is the main system:

• Use 's with a singular noun.
  Example: “Maria's bag is on the table.”
• Use s' with a plural noun that ends in -s.
  Example: “The teachers' lounge is very comfortable.”

3. Irregular Plural Nouns

If the plural does not end in -s, add 's as usual.

Examples:

• “The children's books are on the shelf.” → The books belong to the children.
• “The men's coats are by the door.” → The coats belong to the men.

4. Two Owners

Two Owners, One Thing

If two or more people share one thing, add the 's to the second name only.

Examples:

• “Anna and Ben's car is parked outside.” → The car belongs to both Anna and Ben.
• “Susan and Adam's house is down the road.” → The house belongs to both Susan and Adam.

Two Owners, Two Things

If each person owns separate things, add ’s to each name.

Examples:

“Tom’s and Jerry’s houses are on the same street.” → Tom has one house, Jerry has another.
“Anna’s and Ben’s cars are both red.” → Anna has a red car, Ben has a red car too.

5. Names Ending in S

When a name ends in s, the most common written form adds 's: James's bike, Chris's dog. You may also see James' or Chris' — both are acceptable.

Examples:

• “James's bike is new.” / “James' bike is new.” → Both spellings are correct.
• “Chris's dog is very friendly.” / “Chris' dog is very friendly.” → Both spellings are correct.

Tip: In everyday writing, James's and Chris's are the most common forms.

6. Compound Nouns and Phrases

Sometimes the owner is a word made of two or more parts joined together, like sister-in-law or mother-in-law. For compound nouns (words with hyphens like sister-in-law), add 's to the last part. For phrases describing someone (like “the bus driver”), add 's to the last word.

Examples:

• “My sister-in-law's house is very big.” → The house of my sister-in-law.
• “My best friend's father works in a hospital.” → The father of my best friend.
• “The shop owner's keys are on the counter.” → The keys of the shop owner.

7. Common Mistakes and How to Avoid Them

1. Don't confuse possessive 's with plural s
   • Plural: “The dogs are outside.”
   • Possessive: “The dog's ball is outside.”
2. Be careful with names ending in s
   • “Jess's book” → Correct
   • “Jess book” → Incorrect
3. Remember that 's can also mean 'is' as a contraction
   • “Tom's happy today.” → Tom is happy today.
   • “Tom's bag.” → the bag belongs to Tom.

8. Summary and Key Rules

The possessive 's is very common. It can show:

• Ownership (Anna's book)
• Plural ownership (teachers' lounge)
• Shared items (Tom and Jerry's house)

Tip: Focus on the noun that owns something and decide if it's singular, plural, or part of a compound. Then apply the correct 's or s' rule.