Clitic doubling
Hello everyone.
This is a grammatical thing that I see all the time while reading where the indirect object pronoun and the full indirect object are both written. I was wondering if there was a particular grammar rule that tells me when I should use it.
Example: Me gritaban a mí.
Is there a rule or do you just need to learn which verbs tend to have it and which verbs don't.
I apologize if the question is unclear or contains mistakes... English is not my first language. If you don't understand it I would gladly try to explain it better 
Thanks in advance!
1 Answer
Hopefully I got it:
If the actual direct or indirect object is a noun (not a pronoun):
If the noun is before the verb, the object pronoun must be included, whether it is indirect or direct.
If the noun follows the verb, the object pronouns are not obligatory, but it is normal to include the indirect one and not the direct one:
Juan le dio el anillo a Maria- Juan gave the ring to Maria. Here I include le= a Maria as the indirect object pronoun, I do not include a pronoun for the direct object (el anillo) which would be lo.
El anillo, Juan se lo dio a Maria- I moved El anillo to the front for emphasis. Because it is before the verb, lo must be included to mark it as a direct object (Juan has to be the subject as there is no a in front of Juan). I keep the le for a Maria but change it to se because le becomes se before lo or la.
If the actual direct or indirect object is a pronoun:
If you are just using pronouns then the duplication only serves to emphasize it. It is not necessarily based on the verb, although the emphasis or contrast might be more common in verbs such as gustar than some others
¿Le dio Juan el anillo a Maria? Sí, Juan se lo dio a ella. Here the "a ella" emphasizes to her not to someone else (maybe he had several girls lined up, maybe you want to emphasize some emotion about his choice with your tone in it).
The sentence Juan le dio el anillo a ella emphasizes her. The sentence Juan le dio el anillo. means the same without the emphasis on her. The sentence Juan dio el anillo a ella is incorrect grammar. It is a bad sentence.
