I am writing a card to an adult so do I use

Le deseo or la deseo? Normally te deseo would refer to a friend.....so to be formal which do I use?
Le is indirect object and se is direct object right?
My answer: la deseo

2 answers

Le deseo
If you are studying castellano and therefore use leísmo, the Direct Object would be "le deseo" for a man and "la deseo" for a female.

Leísmo: Leísmo ("using le") is a dialectal variation in the Spanish language that occurs largely in Spain. It involves using the indirect object pronoun le in place of the (standard) masculine direct object pronoun lo, especially when the direct object refers to a male person.

However, you "might" use the Indirect Object Pronoun "le" if your meaning is: I wish FOR YOU...

In any even, you are correct that Te deseo IS familiar and not to be used here.

Sra