The form of the possessive/genitive case

's is used with singular nouns and plural nouns not ending in s:
    a man's job                      the people's choice
    men's work                      the crew's quarters
    a woman's intuition           the horse's mouth
    the butcher's (shop)          the bull's horns
    a child's voice                  women's clothes
    the children's room           Russia's exports 

A simple apostrophe (') is used with plural nouns ending in s:
    a girls' school                   the students' hostel
    the eagles' nest                 the Smiths' car 

Classical names ending in s usually add only the apostrophe:
    Pythagoras' Theorem      Archimedes' Law  Sophocles' plays 

Other names ending in s can take 's or the apostrophe alone;
    Mr Jones's (w Mr Jones' house)      Yeats's (or Yeats') poems 

With compounds, the last word takes the's:
        my brother-in-law's guitar 

Names consisting of several words are treated similarly:
    Henry the Eighth's wives     the Prince of Wales's helicopter 

's can also be used after initials:
        the PM's secretary         the MP's briefcase the VIP's escort 

Note that when the possessive case is used, the article before the person or thing
'possessed' disappears:
        the daughter of the politician = the politician's daughter
        the intervention of America = America's intervention
        the plays of Shakespeare = Shakespeare's plays

Ali Baba and the Forty Thieves

Ali Baba was such a poor man that he had only one shoe for his two feet. Even the mice in his house were hungry.

One day, his wife said, "We have no food in the house. No rice. No potatoes. Go and collect leaves in the forest so that I can make a soup."

Ali was a lazy man. He looked for leaves for about ten minutes and then he climbed a tree to sleep. He was afraid of wolves. When he woke up, he was surprised to see forty thieves on forty horses. They stopped in front of a big rock.

"Open Sesame!" shouted the leader. A door on the rock opened. The thieves carried sacks full of gold into the cave. When they had finished, the leader shouted.

"Close Sesame!" and the door closed. As soon as the thieves had disappeared Ali Baba jumped downfrom the tree, said, "Open Sesame" and
went into the cave.

There were shelves all around the walls. The shelves were full of sacks. And the sacks were full of gold. Ali took a sack home with him.

Unfortunately, one of the thieves saw Ali's footprints on the sand. He followed them to Ali's home. He took out his knife and made a cross on the door.

"Now I shall know which house it is," he said.

He rode off to get the other thieves. But Ali had seen the thief.

He and his wife took brooms and swept away the footprints. Then he made crosses on every door at the street. When the forty thieves arrived they had their knives between their teeth. But they couldn't fi  nd either Ali – or the gold. And Ali and his wife lived happily ever after.

What Is Thunder and Lightning?

Lightning is a sudden, violent flash of electricity between a cloud and the ground, or from cloud to cloud. A lightning fl  ash, or bolt, can be several miles long. It is so hot, with an average temperature of 34,000° Centigrade, that the air around it suddenly expands with a loud blast. This is the thunder
we hear.

Lightning occurs in hot, wet storms. Moist air is driven up to a great height. It forms a type of cloud called cumulonimbus. When the cloud rises high enough, the moisture freezes and ice crystals and snowfl  akes are formed. These begin to fall, turning to rain on the way down. This rain meets more moist air rising, and it is the friction between them which produces static electricity. When a cloud is fully charged with this electricity, it discharges it as a lightning flash.