Juan plays the trumpet. = He plays the trumpet.	Juan toca la trompeta. = Él toca la trompeta.
Juan plays with María. = Juan plays with her.	Juan juega con María. = Juan juega con ella.
He hasn't any brothers. = He hasn't any.	Él no tiene ningún hermano. Él no tiene ninguno.

Depending upon the grammatical function of the noun that gets replaced by a pronoun we make a difference between:

• Personal Pronouns (pronombres personales)
• Subject pronouns (that stand for the grammatical subject) (pronombres de sujeto)
• Object pronouns (that stand for the grammatical direct or indirect object) (pronombres de complemento directo, indirecto o preposicional)
• Reflexive Pronouns (that refer back to the subject of the sentence) (pronombres reflexivos)
• Interrogative Pronouns (that are used to ask for persons, animals, things, events, etc.) (pronombres interrogativos)
• Demonstrative Pronouns (that are used to point out persons or things) (pronombres demostrativos)
• Possessive Pronouns (that are used to show possession or ownership) (pronombres posesivos)
• Relative Pronouns (that are used to introduce relative clauses) (pronombres relativos)
• Indefinite Pronouns (that are used to refer to unidentified persons or things) (pronombres indefinidos)