How to Use the Imperfect Tense and the Preterite Tense

The Imperfect Tense and The Preterite Tense are both ways to talk about actions that happened in the past. Learning when to use which is one of the more frustrating things a Spanish student has to do because we just don't think the same way in English. We have only one past tense conjugation and it tells us simply one thing — the action happened in the past. Consider this sentence:

I went fishing.

What's the time frame of this action? Clearly the fishing took place in the past. However, we don't know anything more about the situation than that, do we? For example: did the fishing occur once or many times?

To get across to the reader or listener important information such as when or how often this event occurred we have to add some extra information:

I went fishing yesterday.
I went fishing every morning.

In the first sentence we know that the fishing happened once. In the second we know it happened repeatedly.

Most of the decision to use either the preterite or the imperfect boils down to the difference in the two example sentences above. In Spanish, information as to whether the event happened once or went on for a while is "built in" to the conjugation you choose.

Let's start with the imperfect ...

When to Use the Imperfect Tense

Note: For this lesson imperfect conjugations will be indicated like this: imperfect conjugation

Repeated, Usual, Habitual Actions

We mainly use the imperfect tense when talking about repeated, usual, or habitual actions in the past:

Los sábados yo jugaba con mi vecino.
On Saturdays I played with my neighbor.

Usualmente él llegaba temprano.
He usually arrived early.

Mi madre siempre me preparaba desayuno.
My mother would always prepare breakfast for me.

In the first example we use the imperfect jugaba (rather than the preterite jugué) because we see this happened repeatedly, over the course of many Saturdays. In the second we use the imperfect llegaba (rather than the preterite llegó) because we know from the context that this was a usual activity. And in the third we use preparaba (rather than preparó) because this was a habitual action that happened often.

Words such as "always," "frequently," "generally," "never," "often," "usually," "used to," and "would" clue us into the fact that we should use the imperfect.

Background Information

We use the imperfect to describe the setting or provide background information such as what people, places, or conditions were like at some unspecified time in the past:

La ciudad era vieja y sucia.
The city was old and dirty.

La sirenita se llamaba Ariel y tenía seis hermanas.
The little mermaid was named Ariel and she had six sisters.

Times and Ages

We also use the imperfect to state the time and people's ages in the past:

Isabel tenía ocho años.
Isabel was eight years old.

Era la una de la mañana.
It was one in the morning.

Ongoing Actions

Additionally, we use the imperfect to describe actions that were ongoing or in progress at some point in the past. This is roughly equivalent to using the imperfect progressive. In these sentences, when the action began or ended is unimportant, it just happened to be occurring at that moment:

Rosa hacía su tarea a las 9:00.
Rosa was doing her homework at 9:00.

Yo dibujaba el lunes por la mañana.
I was drawing Monday morning.

When to Use the Preterite Tense

Note: For this lesson preterite conjugations will be indicated like this: preterite conjugation

Single, Completed Actions

If the imperfect is primarily used to describe actions that happened over and over again, what is the preterite used for? You're right! To talk about single, completed actions that took place at specific points in time:

El sábado yo jugué con mi vecino.
On Saturday I played with my neighbor.

Ayer él llegó temprano.
Yesterday he arrived early.

Mi madre me preparó desayuno esta mañana.
My mother prepared breakfast for me this morning.

Since the actions referred to in these examples are one-time events, we choose the preterite. In the first case we use the preterite jugué (instead of jugaba) because the playing we're referring to only occurred once, on Saturday. Likewise, in the second case we choose the preterite llegó (instead of llegaba) because we're referring to one arrival, yesterday. And lastly, mother prepared breakfast once, this morning.

Time cues such as length of time, or a specific year, season, month, day, or time of day indicate that we should be using the preterite.

The Imperfect vs. The Preterite

Differences in Meaning

This might be a good time talk about why it's called the "imperfect" tense. It doesn't have anything to do with quality, but rather the idea that the action is "incomplete;" it doesn't have a specific beginning or end. Because we're using the imperfect and not attaching a definite time frame to these actions, we're indicating that when they began and when (or if) they ended is unknown or unimportant. For example:

Marcos se sentía enfermo.
La plaza estaba decorada para la fiesta.
Esmeralda tenía que regresar a casa.
Hacía frío.

"Marcos was feeling sick." (We don't know exactly when he started feeling bad or if he's now feeling better.) "The plaza was decorated for the party." (Who knows for how long?) "Esmeralda was supposed to return home." (We're not sure when or if she did.) "The weather was cold." (When or if the weather changed isn't important.)

On the other hand…

Let's look at the same examples, this time with preterite conjugations and definite time frames. Now we are explicitly stating when the action started, lasted, or ended, and therefore indicating that the time frame is important. Because of this we are subtly indicating that a change has occurred:

La semana pasada Marcos se sintió enfermo.
La plaza estuvo decorada por un mes.
Esmeralda tuvo que regresar a casa el martes.
Hizo frío hace dos días.

"Last week Marcos got sick." (Marcos started feeling sick last week.) "The plaza was decorated for one month." (But it isn't anymore.) "Esmeralda had to return home on Tuesday." (And she did.) The weather was cold two days ago." (But it's much warmer now.)

Due to the differences in emphasis between a preterite and imperfect conjugation, some verbs will have significant differences in meaning when translated. Hopefully by now these variations will make some sense to you. Notice how the preterite tends to signal a change:

	imperfect:	preterite:
conocer:	Conocía a Ana. I knew Ana.	Conocí a Ana. I met Ana.
poder:	Podía salir. I was able to leave.	Pude salir. I managed to leave.
no poder:	No podía terminar. I was not able to finish.	No pude terminar. I failed to finish.
querer:	Quería hablar. I wanted to speak.	Quise hablar. I tried to speak.
no querer:	No quería leer. I didn't want to read.	No quise leer. I refused to read.
saber:	Sabía la razón. I knew the reason.	Supe la razón. I found out the reason.
tener:	Tenía guantes. I had gloves.	Tuve guantes. I got gloves.

The Imperfect and the Preterite Together

It's not at all uncommon to have both preterite and imperfect conjugations in the same sentence. In fact, it happens a lot. The imperfect (or the imperfect progressive) is used to explain what was happening when a preterite action occurred:

Los perros dormían cuando Carlos entró.
The dogs were sleeping when Carlos entered.

Cuando llegaron a la carretera el tiempo hacía calor.
When they reached the highway the weather was hot.

Yo me caí mientras que estábamos corriendo.
I fell while we were running.

For Visual Learners

If you're still having trouble with the imperfect and the preterite, sometimes it can be advantageous to imagine a time line. On the right side is the present (we'll ignore the future for now). Toward the left is the past.

If you know with any certainty when the action happened, you should be able to pinpoint on the time line (with an arrow) exactly when it happened. For example:

On Saturday his friend went to the baseball game.

On the other hand, if you find it difficult to pin down, you may have to indicate only an indefinite range (with a squiggly line) of the action. For example:

His friend was a good baseball player.

So, what good does this do us? Whenever you would draw an arrow, you should use the preterite; whenever you would draw a squiggly line, you should use the imperfect. Like this:

El sábado su amigo fue al partido de béisbol.
Su amigo era un buen jugador de béisbol.

Another example:

Esperanza broke her arm when she was a girl.

This sentence has two verbs which both go on the time line: "broke her arm" and "was a girl." One of the verbs was a one-time event, the other was a situation with an indefinite time frame so we'll use both an arrow and a squiggly line.

Therefore the translation is:

Esperanza rompió su brazo cuando era niña.

One more example:

When Paco was a boy he lived in Oslo for a year.

Childhood has a vague, indefinite time frame so we draw it with a squiggly line. But what do we do with "lived"? It is neither a one-time event, nor is it indefinite. It's actually a range; we know Paco moved to Oslo and left a year later. Since you can pinpoint a beginning and/or and end of an action on a timeline, you should treat it like you would a one-time event.

Therefore:

Cuando era niño Paco vivió en Oslo durante un año.