The Genitive case

Which one is correct?

Singular (only one)

• This is the boy's cat.

• This is the cat of the boy.

• This is the boys' cat.

• This is the cat of the boy's.

Which one is correct?
Plural (more than one)

• Womens liberation is an important thing.
• The liberation of women in an important thing.
• Women's liberation is an important thing.
• The womens' liberation is an important thing.

Which one is correct?
Plural (more than one)

• The bus's wheels are flat.
• The wheels of the bus are flat.
• The wheels of the bus's are flat.
• The bus wheel's are flat.

Which one is correct?
Plural (more than one)

• The dog's food is not very tasty.
• The food of the dog is not very tasty.
• The dog food's is not very tasty.
• The dogs' food is not very tasty.

Which one is correct?
Singular (only one)

• The top of the mountain is close.
• The mountains' top is close.
• The top's mountain is close.
• The mountain's top is close.

Which one is correct?
Singular (only one)

• Swedens's capital is Stockholm.
• The Capital of Sweden is Stockholm.

Which one is correct?
Singular (only one)

• The boy snuck into his girlfriends' room.
• The boy snuck in to his girlfriend's room.
• The boy of the room snuck in to his girlfriend.
• The boy's room snuck into his girlfriend.

Which one is correct?
Singular (only one)

• Do you know Sarah's father.
• Do you know the father of Sarah?
• Do you know Sarahs' father?
• Do you know Sarahs' father's?

Which one is correct?
Singular (only one)

• She wore the princesss' dress.
• She wore the dress of the princess. 
• She wore the princess' dress
• She wore the princess's dress.

Which one is correct?
Singular (only one)

• I am on the world's top.
• I am on the top of the world.
• I am on the worlds' top.
• I top on the world.