Have you ever thought why there is an "a" placed after some verbs in Spanish? If so, chances are you are actually paying attention to the sneaky little words this language is riddled with.
First, it is important to remember that the word "a" can be used in different situations and in different ways, some of which are as simple as the Spanish contraction a + el = al or as tricky as the personal "a."
If English is your first language, you might have trouble understanding how to use it, because it probably feels a bit unnecessary. However, since there is no English equivalent for the personal "a," it's your job to grasp the ins and outs of this grammar rule as you will eventually need to use it.
If you have studied direct objects in Spanish before, you probably remember that direct objects are the things or people receiving the action of a verb. For instance, when you say veo el carro (I see the car), "el carro" is the direct object. Pretty easy, right?
Now, things get a bit difficult when the direct object is a specific person as opposed to a thing. In English, for instance, you'd say, "I see Robert." If translated literally, yo veo Robert would be a rather awkward sentence in Spanish. In this case, Robert is the specific object of the verb "ver," which means you have to add the personal "a" after it.
Yo veo a Robert is the grammatically correct sentence.
There is nothing in English directly comparable to this structure. Yes, you will be understood if you leave out the personal "a," but you have to get used to using it for proper grammar.
The rule is simple: if the direct object is a thing, don't use the personal "a." If the direct object is a person, however, do make sure to insert it after the verb.
Here are several examples where you can see the personal "a" in action. Notice how animals can also be treated as a person, hence why the personal "a" needs to be used.
Yo veo a María todos los días. -- I see María every day.
Quiero mucho a Daniel. -- I love Daniel very much.
Visité a Sandra en Francia. -- I visited Sandra in France.
Ella besó a Robert en la mejilla. -- She kissed Robert on the cheek.
No conozco a Julio. -- I don't know Julio.
Nuestro jefe llamó a Victoria. -- Our boss called Victoria.
Los niños esperan a su tía Carla. -- The kids wait for their aunt Carla.
Sacó a mi perro a pasear todos los días. -- I walk my dog every day.
If there is more than one direct object that's a specific person, you use the personal "a" for every one.
Veo a Pedro y a Robert todos los días. -- I see Pedro and Robert every day.
Ella escucha a María y a Carlos detenidamente. -- She listens to María and Carlos carefully.
Condujo a José y a Carla a la tienda. -- He drove Jose and Carla to the store.
You should also know that even when the direct object isn't a name, but it still refers to a specific person, you have to use the personal "a."
Ella ama a sus padres. -- She loves her parents.
Mi mamá visitó a sus amigos en Francia. -- My mom visited her friends in France.
Los niños esperan a su mamá. -- The kids wait for their mother.
No conozco a tu profesor de inglés. -- I don't know your French teacher.
Él besó a tu hermana en la mejilla. -- He kissed your sister on the cheek.
Busco a mi amigo. -- I'm looking for my friend.
Even though the friend is unnamed, you're picturing a face in your head, right?
Estoy viendo dos computadoras. -- I am watching two computers.
Estoy buscando un trabajo. -- I am looking for a job.
Tengo tres hermanos. -- I have three siblings.
Hay tres personas en la oficina. -- There are three people in the office.
All in all, if you want to master this structure, you have to practice using it on a daily basis. Listen to native speakers, learn fixed phrases, and use it as often as you can. You'll see the difference. Happy learning!