There are some basic rules that you should bear in mind when you are using possessive nouns, especially in writing.
Singular Possessive Nouns - You can make a singular noun into a possessive noun by just adding an apostrophe and an ‘s’ in most cases. However, there are a few exceptions. For singular nouns ending in ‘s’, you can just add the apostrophe to make it a possessive noun.
For example:
I borrowed Angel’s white shoes for the event.
The new Malayalam movie’s rating is pretty high.
Plural Possessive Nouns - For plural nouns, you can just add an apostrophe to show possession or ownership.
For example:
The boys’ clubs are very competitive.
All the clocks’ hands have to be changed.