The verb ir, like its English counterpart to go, has several meanings and sometimes you can´t figure them out by considering indivual parts of the expression. “Ir” is usually used with the preposition a, when it means direction or future time:

Voy a estudiar para la prueba. – I´m going to study for the test.
Voy a la iglesia los domingos por la mañana. – I go to church on Sunday mornings.

Here are some other common uses of ir:

1. Ir en + name of the vehicle – to go, travel (by a certain vehicle)
¿Cómo vas a la escuela? Voy en autobús. (How do you go to school? I go by bus.)

2. Ir para + verb – to go in order to do something
Mi hermano va para conocer los padres de su novia. – My brother is going to meet his girlfriend´s parents.

3. Ir para + job – be likely to become
Juan va para abogado. – Juan is going to become a lawyer.

4. Ir + gerund – to do something, usually slowly or laboriously
Voy aprendiendo español. – I´m learning Spanish (little by little).

5. Ir tirando – to get by, make ends meet
¿Cómo van tus estudios? Voy tirando. (How are you getting along with your studies? Well, I´m getting by.)

6. Ir de – 1. to be about (movie, book); 2. to think about yourself as.
La película Into the Wild va de un muchacho que dejó todo por seguir en un viaje hacia Alaska. (The movie Into the Wild is about a guy who left everything to go on a trip towards Alaska.)
María va de muy inteligente pero por poco no suspende algunas asignaturas. (Maria thinks she´s smart but she almost flunked some subjects.)

7. Ir por – 1. to search for; 2. fetch; 3.to be at a certain point (task)
Vamos por una escuela para nuestra hija. (We´re looking for a school for our daughter.)
Voy a la tienda por leche. (I’m going to the shop to get some milk.)
Maestra, no se preocupe; ya voy por la mitad del libro. Prontito lo termino. (Miss, don´t worry; I´m halfway through the book. I´ll finish it pretty soon.)

8. Irse – to go away
¡Vete de aquí ahora, no quiero verte más! (Go away now, I don´t want to see you anymore!)

See you next time!