Preterite vs Imperfect

The preterite and imperfect are two of several ways to express the past in Spanish, but also the two that seem to cause Spanish learners the most problems when it comes to understanding when to use them. Let's tackle them one at a time and then compare the two. Once you've read this article you will have a strong understanding of how to use each tense and when to combine them.

When to use the Preterite

The preterite is used to describe an action or event that is measurable in some way. For example, it is used to describe an action that was totally completed in the past.

In this example, the person speaking ate their breakfast and that event or action was completed. They are no longer eating their breakfast and equally, it is not an action that went on for a long time in the past. At a single point of time (this morning), they started and finished eating their breakfast. The action has been completed.

The preterite is also used to describe an action that completed at a definite, specific time in the past, e.g.

There are many key time expressions that would act as a trigger for using the preterite past tense in Spanish. Here are some examples:

How to conjugate verbs in the Preterite tense

Most verbs are regular in the preterite tense. This means that they all follow a pattern. The preterite is formed by firstly removing the -ar, -er or -ir ending from the infinitive form and then applying the preterite ending. Here are examples of how regular -ar, -er and -ir verbs are formed.

Stem changing verbs in the Preterite

As with the present tense, there is a pattern of stem changes in the preterite tense. In broad terms:

In the preterite tense, some verbs have spelling changes that are required to maintain the hard sound of the consonants g and c with -que and -gue. These changes only apply to the yo form of the verb.

Spelling Changes: c → qu and g → gu

Spelling Changes: z → c

Some verbs have an irregular spelling only in the third person singular. Look at these examples:

Irregular Verbs in the Preterite

Some of the most common Spanish verbs are irregular in the preterite. They have unique stems and slightly different endings. Here are some key irregular verbs you need to know:

The Imperfect Tense

Now we come to the imperfect tense. Unlike the preterite, the imperfect is used to talk about an action in the past that was not completed.

First, let's look at the imperfect. Then we will compare the two. The imperfect is used when an event took place over a long or unknown period of time in the past. For example:

In this example, we don't know exactly how long the person lived in Italy for. All we know is that they no longer live there. And they may have lived there for many years. The action takes place over a long or unknown period of time.

The imperfect is also used to talk about an action that was in the process of taking place. For example:

In this instance, we don't know when the person in question started or stopped listening to the radio. All we know is that at some point in the past, they were in the process of listening to the radio. The action was unfinished or on-going.

Conjugating Verbs in the Imperfect

The great news about the imperfect tense is that most verbs are regular in the imperfect and there are only three exceptions! To form the imperfect, remove the -ar, -er or -ir ending and replace it with the imperfect ending.

Preterite vs Imperfect Comparison

The most important thing to remember is that the preterite is used for completed actions with a clear beginning and end, while the imperfect is used for ongoing, habitual, or background actions.

Examples Using Both Together

In many sentences, you'll use both tenses together. The imperfect sets the scene (background), while the preterite describes what happened (foreground action).

Ser and Estar in the Past

Both ser and estar can be used in preterite and imperfect. The choice significantly affects meaning.