Like its English counterpart "to go," the Spanish verb ir can be used with an incredible variety of meanings. The meanings of phrases using ir can't always be determined logically merely by knowing the meanings of the individual words, so they are best learned through actual use or memorization.
By far the most common expression using ir is ir a followed by an infinitive. For most purposes, it is the equivalent of the English "to go to" followed by a verb. Thus "voy a estudiar" means "I am going to study." This use of ir a is extremely common in Spanish, so much so that in some parts of Latin America it is the de facto future tense. So a sentence such as "Vamos a comprar la casa" can be translated as either "We are going to buy the house" or "We will buy the house."
Here are some other common expressions where ir is used:
- ir a (or, less commonly, ir para) + destination — to go to (a place) — Fuimos a la playa. We went to the beach.
- ir en + name of vehicle — to travel by (type of vehicle) — Voy en autobús. I am traveling by bus.
- ir para + infinitive — to go to verb, to go in order to verb, to go for the purpose of verb — Vamos para conocer a mis padres. We are going in order to meet my parents.
- ir para + type of job or career — to go to become type of job — Pablo va para médico. Pablo is going to become a doctor.
- ir + gerund — to be doing something, usually with the connotation of doing so gradually or laboriously — Voy aprendiendo la lección. I am slowly learning the lesson. Él va construyendo la casa. He is gradually building the house.
- ir tirando — to manage or get by — Vamos tirando por mucha ayuda. We're getting by with a lot of help.
- ir andando, ir corriendo — to walk, to run — Va andando a la escuela. He is walking to the school. Fue corriendo a la escuela. He ran to the school.
- ir de — to be about (when said of a book, movie, speech, etc.) — "El señor de los anillos" va de un hobbit. "The Lord of the Rings" is about a hobbit.
- ir de — to think of oneself as — Roberto va de inteligente. Roberto thinks he's smart.
- ir de, ir con — to be dressed in — Él va con camisa blanca. Ella va de azul. He is wearing a white shirt. She is dressed in blue.
- ir de compras — to go shopping — Fuimos de compras. We went shopping.
- ir por — to search for, to go in search of, to go for — Vamos por una casa nueva. We're off in search of a new house.
- ir por — to reach or to pass (a milestone or task) — Voy por la mitad del libro. I'm halfway through the book.
- ¿Cómo + indirect object pronoun + ir? — How goes it (for you, him, her, etc.)? — ¿Cómo te va? How's it going? ¿Cómo le va a él? How's it going for him?
- irse — to go away — ¡Vete ya! Get out of here!
- irse por las ramas — to beat around the bush, to get sidetracked — El testigo se fue por las ramas. The witness beat around the bush.