Preposition a usage

Question

Hola,In this statement, just wondering why there is the preposition after llamamos?Después de la fiesta llamamos a un taxi.I know we have a lesson on prepositions for movement verbs, and guess this comes under the 'purpose' part of that?Do you have any resources (or planned) to go into this a bit more?Gracias,

Answer

Hola Stuart,
The verb llamar, with its meaning of "calling on the phone" or "calling by shouting" is used with the preposition "a":

Llamé a Juan ayer. 
I called Juan yesterday.
¿Has llamado a tu madre?
Did you call your mum?
Voy a llamar a mi hijo por la ventana para que suba a comer. 
I am going to call my son from the window so he comes up to have lunch.

Here, it is clear we need the "personal a" because we are calling "people".
When we use it with "taxi", we are thinking more about the taxi driver than the car. This is why we use the "a". Using it without the "a" would sound very weird "¡Llama un taxi!" ??
But this is the same when we call a company, a place, an institution...; I imagine this happens because we call to talk to people, not the establishment.

Tengo que llamar a Recursos Humanos para preguntar sobre mi contrato.
I have to call H.R to ask about my contract.
Ayer llamé a Amazon para reclamar mi dinero.
 I called Amazon yesterday to claim my money.
Llama a la oficina y pregunta por Javier.
Call the office and ask for Javier.

I hope this clarified it.
Saludos,
Inma