One of the uses of the apostrophe is to show possession, which means who something belongs to.
For example:
the girl's ball = the ball belonging to the girl
If the ball belongs to more than one girl, we make the world into a plural by adding s, then place the apostrophe at the end of the word.
the girls' ball = the ball belonging to the girls
The word girl is a singular noun, but the word girls is a plural noun (plural means 'more than one').
Most plural nouns in English end in 's' so the apostrophe comes after the 's'.
Sometimes however, a singular proper noun ends in an s. A proper noun always begins with a capital letter and is a naming word for a person or place.
Some examples of proper nouns ending in s are:
Cyprus
Miss Williams
Brussels
When using an apostrophe to show possession with these words, we use the ending 's
For example:
Cyprus's population
James's cat
It's easy for us to become mixed up with these words as they end in s just as plural nouns do, so let's practise!