Pronoun is a word that is used in place of a noun or noun phrases. Pro refers to 'in place of', therefore, Pronoun means in 'place of noun'.

The most frequently used types of pronouns are personal pronouns.

A noun that is replaced by pronoun is called antecedant. 

There are mainly eight types of pronouns - Personal pronouns, Possessive pronouns, Indefinite pronouns, Interrogative pronouns, Intensive or Reflexive pronouns, Relative pronouns, Reciprocal pronouns, Demonstrative pronouns.

1. Personal Pronouns -
   1. These pronouns refer to any particular person or a thing. Their form changes depending on the gender, quantity, person. Some Examples of Personal pronouns are - I, They, He, She, Them, etc.
   2. These have four characterstics - number, person, case and gender
   3. Some examples are - 
      1. You went to movies at 11PM. 
         1. Here You is the personal pronoun - You can be singular or plural.
   4. Subjective pronouns - Pronouns can be used as Subjects - these are called Subjective pronouns. For example - Who, He, She, It, They, Who, I, etc. 
   5. Objective pronouns / Objective case - These are the objects in a sentence. 
   6.  
2. Possessive Pronouns - 
3. Indefinite Pronouns - 
4. Interrogative pronouns - These pronouns are used to form questions. There are five main interrogative pronouns -  What, Which, Whose, who, and Whom.
   1. You may wonder which nouns are being replaced by the interrogative pronouns. To know that, just notice the answer. These pronouns were replacing the noun in the answer. 
   2. Who, whom refers to people while others refer to objects or people.
5. Intensive or Reflexive pronouns - 
6. Relative pronouns -
7. Reciprocal pronouns -
8. Demonstrative pronouns - 
9. Reciprocal pronouns - These pronouns indicates that two or more than two people have carried out an action of some type and each of them have received the consequences of the action simultaneously. The person who performs the action also receives the action in return. There are two reciprocal pronouns - each other and one another.