I looked this question up and found it online. We are supposed to add an apostrophe or 's to indicate possession.
Answer:
The Pilgrims' little ship was uncomfortable.
A sincere person's compliment is a valuable gift,
Mr. King's class has a great Web site.
The class's teacher was quite young,
The pony's rider was too heavy.
Your brother's attitude got him into trouble.
Amy's report card was wonderful.
The little babies' nursery had twelve beds.
I didn't know I was eating your cat's chopped tuna.
The men's clothing suggested they were doctors.
A turkey's intelligence is not overwhelming.
The girls' outfits were exactly the same.
We were proud of Chris's performance.
The king's horses couldn't put him together again.
My horse's name is Swampygoosehoof.
Explanation:
When using the genitive case in English to indicate possession, we add an apostrophe or an apostrophe plus the letter -s to the ending of a noun. This noun should refer to the person (or animal) who owns something, or to whom someone is related. Occasionally, the genitive case can also be used with objects or places.
There are a few rules that must be observed:
1. In general, we add 's to the noun: Ana's paintings are beautiful.
2. If a name already ends in -s, we can add either 's or just the apostrophe: Ross' (or Ross's) apartment is across the street.
3. If a plural word ends in -s, we only add the apostrophe: The boys' toys are scattered all over the room.
4. If a plural word does not end in -s, we add 's: The children's clothes are to your left.
5. If two people own or are related to the same thing or person, we add 's only to the last name: Mia and Sarah's mother is always late.
6. If two people own or are related to different things or people, we must use 's in both names: Mia's and Sarah's mothers are not good friends.
