A pronoun is an indicator referring to in individual. Person pronouns like 'I' or 'me' are used to refer to oneself in various tenses. Usage of pronouns is modified in conditional tenses referring to a possessive context and plurals. In syntax, the context of subjects regarding the pronoun dictates usage when using tenses or creating syntax.
The reference to a person may include use of 'self' with the pronoun, as an added indicator.
Examples of Pronoun:http://www.towson.edu/ows/pronouns.htm