The Imperfect Tense

Formation

There are 2 sets of conjugations for regular verbs in the imperfect tense.

This tense is formed by adding the endings to the stem of the verb.

Here are the endings for regular verbs that end in -ar.

	singular	plural
first person	aba	ábamos
second person	abas	abais
third person	aba	aban

yo hablaba
tú hablabas
él/ella/usted hablaba
nosotros hablábamos
vosotros hablabais
ellos/ellas/ustedes hablaban

Here are the endings for regular verbs that end in -er or -ir.

	singular	plural
first person	ía	íamos
second person	ías	íais
third person	ía	ían

yo bebía
tú bebías
él/ella/usted bebía
nosotros bebíamos
vosotros bebíais
ellos/ellas/ustedes bebían

Usage

In general, the imperfect tense in Spanish will correspond with these English equivalents:
yo hablaba = I was speaking, I used to speak

The imperfect tense is used for past tense actions where there is not a specified completion. This includes habitual/continuous actions in the past. Also note that the imperfect is used for descriptions in the past. 

Vivía en México.  I used to live in Mexico.La casa era verde.  The house was green.

There are several common phrases that indicate that the imperfect tense should be used. It is helpful to remember these types of phrases. Here are some common ones:

always sometimes often/frequently every day every year

siempre a veces; de vez en cuando a menudo; frecuentemente cada día cada año