We have a lot of “tricky” verbs in spanish if you are trying to do a literal translation from english to spanish, some of them are the verbs “ir-venir”, “llevar-traer”.
We could translate “venir” as “to come”, however we would never say “estoy viniendo” (I am coming) in Spanish. Why? Because these verbs in spanish are related to the person who is talking and his location. Everything that comes to his location (from the point of view of the speaker) would be “venir” and everything that goes away from there (even his own body) would be “ir”.
So, if you are walking down the street while talking on your cell phone you would say “estoy yendo” (…to your place, school, or wherever you are going).
If the delivery boy rings your bell, you would say “ya voy” (to the door).
You will use “venir” for example, if you are leaving a friend´s house and you will return to look for some books another day. “Mañana voy a venir a buscar estos libros, ahora llevo muchas cosas”.
“Mis padres vendrán a visitarme a Buenos Aires pronto y yo voy a ir a mi país para Navidad”.
We use the same concept with “traer-llevar”.
Everything that comes to the location where the person is talking would be “traer” and everything the goes far away from there would be “llevar”.
-Mozo, ¿me traería otra copa de vino? (Waiter, will you bring me another glass of wine?).
-Voy a llevar souvenires para mis padres, quizás algo de San Telmo. (I am going to bring souvenirs for my parents, maybe something from San Telmo)
– One idea to illustrate both venir-ir and llevar-traer would be to look at a conversation between two people like this:
o Juan: When are you coming to my house? (¿Cuándo vas a venir a mi casa?)
o Alejandro: I’m going (leaving, coming) in 5 minutes. (Voy a ir en 5 minutos)
o Juan: Are you going to bring a bottle of wine? (¿Vas a traer una botella de vino?)
o Alejandro: Yes, I’m going to bring it. (Sí, voy a llevarla)