To be honest, learning the differences between the two Spanish past tenses was ridiculously difficult for me, as I had lived my whole life speaking English, where verb tenses are not nearly as clearly defined. Today, I'll make it easier for you by explaining the differences that I learned as I was mastering Spanish verb tenses.
Here's a little help from our friend Jordan at Gringo Español
Spanish Preterite Tense
The preterite is used when referring to actions that were completed in the past. When you use the preterite, it also implies that the action had a definite beginning and a definite end. In English, you might say a sentence like Yesterday I cleaned the house for two hours—in this sentence, the timeframe is very specific. Translating this sentence into Spanish, you would use the preterite tense. Another example of the preterite might be I ate five strawberries.
Preterite -ar endings
For regular -ar verbs, to form the preterite you drop the -ar and replace it with the correct preterite ending. Here's an example with the verb caminar (to walk):
+ Preterite Ending
Preterite -er/ir endings
We do the same thing will verbs ending in -er and -ir. Here's an example with the verb comer (to eat):
+ Preterite Ending
Irregular Preterite Verbs
Of course, some verbs will have irregular conjugations in the preterite. Some of the most common of these include: ser, ir, dar, hacer, estar, poner, tener, haber, querer, venir, andar, poder, and saber. You will need to memorize the six preterite forms for each of these irregular verbs.
Irregular Preterite Verbs
Spanish Imperfect Tense
The imperfect is used to denote an action that took place in the past, but the specifics of the timeframe are left up in the air. We use the imperfect in English, too.
They were eating dinner when I arrived.
Using "were" plus the gerund denotes the imperfect past in English. Here, we know that the action of eating dinner took place in the past, but it does not have a definite beginning or end, nor does it matter for the sentence's purpose. We don't know when they stopped eating dinner, but in this sentence it doesn't matter because we are more focused on the fact that they were eating.
Another example of the imperfect in English might be:
I used to go fishing with my dad.
"I used to go" denotes that something used to occur before but now it doesn't. Again when using the imperfect we don't care so much about the details of what happened (when I do, how did I, when did I stop going) the important fact in this sentence is that there was a time when I would go but I no longer go anymore.
Imperfect -ar endings
When forming the imperfect for a regular -ar verb, drop the -ar just like in the preterite conjugation but this time we add the imperfect ending. Here's an example using caminar again:
+ Imperfect Ending
Imperfect -er/-ir endings
Same deal with -er/-ir endings, just drop the infinitive ending and add the imperfect. Here's an example using comer again:
Irregular Imperfect Verbs
Luckily, there are only three verbs that are irregular in the imperfect past: ser, ver, and ir.
Irregular Imperfect Verbs
Some Verbs Change Meaning Depending on Tense
For some verbs, using it in the preterite versus the imperfect can create a slightly different meaning. Compare the translations of these sentences in the preterite versus in the imperfect:
Enter your text here...
Conocí al primer ministro.
(I met the prime minister).
Ya superion de la película.
(They already found out about the movie.)
Tuvo una carta de su abuela.
(He received a letter from his grandmother.)
Quise encontrar el libro.
(I tried to find the book.)
Yo no quise ir al supermercado.
(I refused to go to the supermarket.)
Pudieron comprar un carro.
(They succeeded in buying a car.)
No pudimos abrir la puerta.
(We failed to open the door.)
Conocía al primer ministro.
(I knew the prime minister).
Ya sabían de la película.
(They already knew about the movie.)
Tenía una carta de su abuela.
(He had a letter from his grandmother.)
Quería encontrar el libro.
(I wanted to find the book.)
Yo no quería ir al supermercado.
(I did not want to go to the supermarket.)
Podían comprar un carro.
(They were able to buy a car.)
No podíamos abrir la puerta.
(We weren't able to open the door.)
Distinguishing Between Preterite and Imperfect
What you did vs What you were doing
The basic rule of thumb when it comes to figuring out which tense to use is that the preterite talks about things you did, and the imperfect talks about things you were doing at some point in time, or that you used to do. With some practice, this is fairly easy to remember. Consider these examples:
Toqué el piano - I played the piano (and I finished the action).
Yo tocaba el piano - I used to play the piano; or, you are saying that you were playing the piano when setting the scene for a story.
Me comí la manzana - I ate the apple. The action is complete.
Yo comía la manzana - I was eating the apple (when something else happened).
Yo leí el libro - I read the book (and now I'm done).
Yo leía el libro - I was reading the book (and the start and end times don't matter).
What happened vs The way things were
Another way to look at it is that the preterite is for talking about things that happened in the past, while the imperfect is for the way things were in the past. Using the same sentences:
Toqué el piano - I played the piano (yesterday, or that night, or whatever specific timeframe context provides)
Yo tocaba el piano - I used to play the piano at some point in the past, but I don't anymore.
Me comí la manzana - I ate the apple (yesterday night).
Yo comía manzanas - I used to eat apples (and maybe I don't anymore).
Yo leí el libro - I read the book.
Yo leía libros - I used to read books.
Use context clues
When reading or listening to Spanish, you can use context clues to figure out whether a verb phrase is in the preterite or imperfect tense. Certain temporal phrases are associated with either the preterite or the imperfect. You can also learn these phrases to help you express yourself better.
Phrases that hint toward the preterite:
ayer - yesterday
anoche - last night
después - afterward
durante dos semanas - for two weeks
el mes pasado - last monthel
otro día - the other day
en ese momento - at that moment
entonces - then
esta tarde - this afternoon
hace dos días - two days ago
Phrases that hint toward the Imperfect:
a menudo - often
a veces - sometimes
cada día - every day
muchas veces - many times
nunca - never
siempre - always
todos los días - every day
todo el tiempo - all the time
varias veces - several times
Mastering the Two Spanish Past Tenses
Practice make perfect
One of the most efficient ways to master any Spanish grammatical concept is to practice with another person who can give you feedback and constructive criticism. Story-telling is an excellent form of practicing verb tenses.
Try telling a story to your tutor or friend and having them correct you on your mistakes. Then, have them tell you a story in return, and pay attention to their choice of verb tense.
Another way you can get the hang of Spanish grammar is to watch your favorite TV shows and movies, but turn on Spanish subtitles. Pay attention to the sentences in English that are past tense, and make note of which verb tense they use in the Spanish subtitle.
Other media, such as Spanish-language movies or even videos like these can solidify your Spanish skills. Practice quizzes are also enormously helpful, such as this one.
Distinguishing between the preterite and the imperfect is one of the most challenging aspects of learning Spanish, and it's also one the most important. That being said, it's not impossible. With a little know how and a lot of practice you should be able to use both with no problems
Leave a comment if you have any questions about these two slightly tricky verb forms!