Pronouns are a group of small words that are very widely used, especially in sentence completion exercises, and there are many different types:
The first column shows the pronouns we use when they function as the subject of a sentence, and the second column shows the forms when the pronoun is the object of a verb:
He invited David. (subject)
David invited him. (object)
The next two columns show how these words are used to indicate possession:
This is my book because this book is mine.
When the subject and the object of a verb are the same, we use reflexive pronouns:
I time myself when I run. (I and myself are the same person)
When two people do something and both benefit from the action, reciprocal pronouns are used:
They helped each other because they knew one another.
When we talk about someone without being specific, we use indefinite pronouns:
Is there anything in your left hand?
Yes, there is something in my left hand, there is nothing in my right hand but everything else is in my pocket.