The Use of the Infinitive Form, Part 1

As you probably know, the infinitive form is a verb that isn't conjugated to fit any subject. The infinitive ends in the following suffixes only: -ar, -er, and -ir. The main way we use the infinitive is to juxtapose two verbs where the preceding verb is conjugated to the subject and the following verb is in the infinitive. The second verb which is in the infinitive maintains its meaning of "to ....". Note the following two sentences, where the infinitive has its suffix underlined:

Quiero escribir una novela. I want to write a novel.

Necesitamos pasar la noche en el hotel. We need to spend the night in the hotel.

The conjugated verb + infinitive formula can also include a preposition in between the two parts; these prepositions can include a, en, por, para, de, sin, or con. A lot of times, there is no direct English equivalent to these prepositions. Some examples:

Van a venir a nuestra casa mañana. They're going to come to our house tomorrow.

Acaban de volver de su viaje a España. They just got back from their trip to Spain.

¿Tardaste en llegar al cine? Were you late in getting to the theater?

Me intereso por jugar al ajedrez. I'm interested in playing chess.

Pasaré el verano en México para relajarme un rato. I will spend the summer in Mexico in order to relax for a while.

Ella se acostó sin cepillarse los dientes. She went to bed without brushing her teeth.


The infinitive is also used after various prepositonal phrases, such as al, antes de, a pesar de, con el objeto de, después de, en lugar de, and en vez de.

Al empezar la clase, los estudiantes se callaron. Upon beginning class, the students stopped talking.

Entregué el ensayo antes de finalizarlo. I turned in the essay before finishing it.

No tomé nada a pesar de tener sed. I didn't drink anything in spite of being thirsty.

Marcos se matriculó en la Universidad con el objeto de sacar un título de ingeniería. Marcos enrolled at the University with the intention of earning an Engineering degree.

Puse mis platos en el lavaplatos después de cenar. I put my plates in the dishwasher after eating dinner.

Fui al cine en vez de asistir la fiesta tuya. I went to the movies instead of attending your party.

Sigue estudiando,

Professor Joel