What is the preposition "a" here?
What is the "a" for in the question: ¿A qué amigo necesita Estela más?
2 Answers
It's commonly referred to as the personal "a". Spanish uses it when the direct object of the verb is a person or animal that one has feeling for (a pet).
It's harder to see in a question. Which friend does Estela need more? The direct object in your sentence is amigo (person) so it is preceded by "a". The qué here is just an interrogative adjective modifying amigo. (which friend). Notice how the lack of the personal "a" before Estela helps us to know that Estela is the subject and not the direct object of the verb since immediately following the verb is where we usually find the direct object in English sentences. This use of a personal "a" before direct objects is very useful in Spanish sentences where the subject often follows the verb.
Without the personal "a" you might misinterpret the sentence to be "Which friend needs Estela more?" (Estella now being the direct object, rather than the subject.)
Llama por teléphono a Juan y dile que no vamos a ir.
Call John and tell him that we are not going.
Since John is a direct object (person) it is preceded by the personal "a".
Notice in the tell him that him is an indirect object and has no personal "a" even though, it is a person.
I forgot to mention that the "a" is not translated. Llama (por teléfono) a Juan is Call John; not call to John, at John or any other preposition.
Have a look at this excellent "personal a" reference article.
