Imperfect ER/IR Verbs: comía, vivía...

This grammar works by changing the tail of the verb. You take the base meaning and add a sense of duration. In English, we often say "used to" or "was doing." In Spanish, we just change the ending to -ía. This ending stays consistent across almost all -er and -ir verbs. It is one of the most regular patterns in the language. You don't have to worry about stem changes here. If a verb is a nightmare in the present tense, it is usually a dream in the Imperfect. It is the grammar equivalent of a Sunday morning. Everything is slow, relaxed, and predictable.

1. 1Start with the infinitive verb like comer or vivir.
2. 2Remove the last two letters (-er or -ir).
3. 3You are left with the stem: com- or viv-.
4. 4Add the new endings based on the person.
5. 5Yo: -ía (comía / vivía)
6. 6Tú: -ías (comías / vivías)
7. 7Él/Ella/Usted: -ía (comía / vivía)
8. 8Nosotros: -íamos (comíamos / vivíamos)
9. 9Vosotros: -íais (comíais / vivíais)
10. 10Ellos/Ellas/Ustedes: -ían (comían / vivían)
11. 11Every single one of these endings has an accent on the 'i'. Do not forget that little mark. It is the secret sauce. Without it, the word loses its past-tense magic.

Use this tense for habits. Did you eat cereal every morning in 2010? Use comía. Use it for descriptions. Was your first car blue? Use era (from ser). Use it for background information. If you are telling a story about a robbery, use it for the setting. "The sun was shining." "I was drinking coffee." It is perfect for age. "I was ten years old" is tenía diez años. Use it for mental states. "I wanted a pizza" is quería una pizza. It is also great for telling time in the past. "It was two o'clock" is eran las dos. Think of it as the "setting the scene" tense.

Do not use this for one-time events. If you ate a taco yesterday and that was it, use the Preterite. If you moved to a new house on Tuesday, use the Preterite. The Imperfect hates deadlines. It hates specific start and end times. If you can say exactly how many times you did something, don't use the Imperfect. For example, "I lived there for three years" usually takes the Preterite. Why? Because you defined the time limit. The Imperfect is for the blurry, beautiful, and repetitive parts of life. It is not for the items on your completed to-do list.

The biggest mistake is forgetting the accent mark. Every single ending needs that accent on the 'i'. If you write comia, it looks like a typo. Another mistake is mixing up the yo and él forms. They are identical in this tense. Context is your best friend here. Use the pronoun yo if you need to be clear. Some people try to use stem-changes from the present tense. Don't do it. Entender becomes entendía, not entiendía. Keep it simple. Also, don't use it for actions that interrupted something else. That is a job for the Preterite.

Compare this to the -ar verbs in the Imperfect. Those use -aba. For example, hablaba. The -er and -ir verbs use -ía. It is a sharper, cleaner sound. Compare it to the Preterite comí. Comí means "I ate it and I am done." Comía means "I used to eat it" or "I was eating it." Think of the Preterite as a dot on a timeline. Think of the Imperfect as a long, wavy line. In a job interview, you might use Preterite for "I finished my degree." You would use Imperfect for "I worked there for a long time." One is a fact. The other is a description of your experience.