Although normally prepositions are not used in front of direct objects, in Spanish there is a special preposition called the personal a which precedes direct objects that refer to people, personified nouns, and animals.
Por ejemplo …
|Veo a mi hermano.||I see my brother.|
|¿Quieres a Miguel?||Do you like Miguel?|
|¡Invitemos a nuestros profesores!||Let’s invite our teachers!|
|Todo el mundo teme a la muerte.||Everyone fears death.|
|Compré a un perro.||I bought a dog.|
The personal a is also used in front of pronouns that replace people.
|Veo a alguien.||I see someone.|
|No quiere a nadie.||He doesn’t love anyone.|
|Invité a mi hermano.
¿Invitaste a lo mío?
|I invited my brother.
Did you invite mine?
The personal a is used in front of interrogative words like quién and cuánto when the answer to the question requires the personal a.
|¿A quién llamaste?
Llamé a Paco.
|Who did you call?
I called Paco.
|¿A cuántos conoces?
Conozco a Ana y Luís.
|How many (of the people) do you know?
I know Ana and Luís.
The personal a is usually not used after the verb tener, with collective nouns, or with nouns referring to unspecified people.
|Tengo dos hermanos.||I have two brothers.|
|Vi el grupo ayer.||I saw the group yesterday.|
|Buscamos un cantador.||We’re looking for a singer.|