The six indirect object pronouns in spanish are:
These type of pronouns are written before the verb, when the sentence has only a conjugated verb, for example:
La profesora le dio un libro a Juan
There is another case, in which the sentence has two verbs:
So, the Indirect Object Pronoun is written after the infinitive verb and the conjugated verb, for example:
The sentence without the Indirect object pronoun:
Yo voy dar la pelota a Juan
voy is the verb in infinitive form and dar is the second verb
The same sentence, now using the Indirect object pronoun:
Yo voy a darle la pelota
voy is the verb in infinitive form and the pronoun le comes after the second verb
Note that these kind of pronouns are also used to replace the Indirect object in the sentence
