The past progressive presents an action in progress within a moment of the past. It does not view the action as closed, but as something that was happening. The basic form is estar in imperfect + gerund: estaba hablando, estábamos comiendo, estaban viajando. In narration, it marks the part of the action that remained open when observed from the past. That is why it fits well with concrete moments, scenes, and actions that had not yet finished.

Verb	Subject	Infinitive	Conjugation
	vosotros	estar
	yo	estar
	nosotros	estar
	ellos	estar
	él	estar
	tú	estar

Imperfect of estar for the past progressive

Subject	Infinitive	Conjugation
yo	estar	estaba
tú	estar	estabas
él	estar	estaba
nosotros	estar	estábamos
vosotros	estar	estabais
ellos	estar	estaban

Scramble

The base of the past progressive is estar in imperfect. Its forms are estaba, estabas, estaba, estábamos, estabais and estaban. Each one corresponds to the person of the subject: yo estaba, tú estabas, él estaba, nosotros estábamos, vosotros estabais, ellos estaban. After that form comes the gerund of the main verb: estaba leyendo, estábamos saliendo, estaban trabajando. The gerund never changes with person; it changes only estar.

Verb	Subject	Infinitive	Conjugation
	verbo hablar	hablar
	verbo trabajar	trabajar
	verbo mirar	mirar
caminhar	verbo caminar	caminar

Formation of regular gerunds in ar

Subject	Infinitive	Conjugation
verbo hablar	hablar	hablando
verbo trabajar	trabajar	trabajando
verbo mirar	mirar	mirando
verbo caminar	caminar	caminando

Scramble

Verbs in -ar form the gerund with the stem + -ando. Thus, hablar becomes hablando, trabajar becomes trabajando, mirar becomes mirando and caminar becomes caminando. The ending -ando is added directly to the verb stem. In the past progressive, these forms appear after estar in imperfect: estaba hablando, estaban trabajando, estábamos caminando. The gerund keeps the idea of an ongoing process.

Verb	Subject	Infinitive	Conjugation
	verbo correr	correr
	verbo vivir	vivir
	verbo comer	comer
	verbo escribir	escribir

Formation of regular gerunds in er and ir

Subject	Infinitive	Conjugation
verbo comer	comer	comiendo
verbo vivir	vivir	viviendo
verbo escribir	escribir	escribiendo
verbo correr	correr	corriendo

Scramble

Verbs in -er and -ir form the gerund with the stem + -iendo. That is why comer gives comiendo, vivir gives viviendo, escribir gives escribiendo and correr gives corriendo. The form works the same for both groups. In the past progressive, it combines with estar in imperfect: estaba comiendo, estábamos viviendo, estaban escribiendo. When a verb ends in -er or -ir, the regular gerund almost always ends in -iendo.

Frequently used irregular gerunds

Idea
The verb to say changes its root and form saying.
The verb to go forms going to indicate movement or progress.
The verb to sleep forms sleeping with a change in the root.
The verb to read forms reading with a change in the root.
The verb to ask for forms asking with a change in the root.

Some verbs change their stem when forming the gerund. Decir gives diciendo, ir gives yendo, dormir gives durmiendo, leer gives leyendo and pedir gives pidiendo. In decir and pedir, the root vowel changes; in dormir, the vowel also changes; in leer, the sound is kept with y to avoid a difficult sequence; in ir, the gerund is completely irregular. These forms are used the same as the regular ones after estar: estaba diciendo, iban yendo, estaban durmiendo.

Use of the past progressive for a past moment

Usage	Explanation
Concrete moment	Use the past progressive when you want to show an action in progress at a past moment.
Scene detail	Used to paint what was happening exactly at that moment without saying the action ended.

To talk about an action that was continuing at a past moment, you use estar in imperfect + gerund. A las ocho estaba leyendo places the reading as something in development at that hour. Mientras esperábamos, él estaba haciendo una llamada presents the action as active at that point in the past. The focus is not on starting or finishing, but on the process itself. That sense appears with time markers like a esa hora, en ese momento or cuando llegué.

Use of the past progressive with interruption

Usage	Explanation
Interrupted action	Use the past progressive for an action in development when another action past interrupts it.
Event that interrupts	The second action usually appears in preterite to show the sudden cut.

When an action was in progress and another one interrupts it, the past progressive describes the action in progress and the preterite marks the interruption. Estaba comiendo cuando llamaste shows the meal as an open process and llamaste as a punctual event that interrupts it. It also works with other combinations: estábamos saliendo cuando empezó a llover, estaba durmiendo cuando sonó el teléfono. The verb in progressive presents the background; the verb in preterite introduces the abrupt change.

Use of past progressive for simultaneity

Usage	Explanation
Parallel actions	Use the past progressive when two actions happen at the same time in the past.
Shared environment	Also used to show that several people were occupied at the same time.

The past progressive is used to show two actions that were advancing at the same time in the past. Estudiaban y escuchaban música can become estaban estudiando y estaban escuchando música when you want to emphasize the parallel development of both actions. It is also used with different subjects: yo estaba cocinando mientras ella estaba trabajando. The relation between the actions is expressed with mientras, a la vez or with two verbs in progressive joined by y.

Narrative use of the background past

Usage	Explanation
Background setting	Use the past progressive to describe the background setting in a past story.
Ambient activity	Used to show what was happening around while the main part of the story occurs.

In narratives, the past progressive creates the background of a scene. Before a main event occurs, it describes what was already happening around it: La gente estaba hablando, los niños corrían y la música sonaba. This is how you build a past atmosphere that surrounds the main action. It also appears at the start of stories: Era de noche. Llovía y los coches estaban pasando lentamente. The progressive paints the activity visible in the scene and places the reader inside the moment.

Contrast between process and completed action

Usage	Explanation
Process in progress	The past progressive highlights an action in progress before something else happened.
Completed action	The preterite presents a complete and closed action in the past.

The past progressive shows an action in development; the preterite presents a completed action. Leía marks the process from within, while leí marks the finished action. In a sentence like estaba leyendo cuando cerró la puerta, the reading was still open. In leyó el libro y cerró la puerta, both actions appear closed. When the aim is to emphasize duration, background, or interruption, progressive is used; when you want to tell finished facts, the preterite is used.

Choice between habit description and process

Usage	Explanation
Past habit	Use the simple imperfect for customs or repeated actions in the past.
Past description	Use the simple imperfect to describe people, places, or states in the past.
Active process	Use the past progressive for an action that was progressing at that moment.

The simple imperfect describes habits, states, and descriptions in the past: vivía en Madrid, iba al gimnasio los lunes, la casa era grande. The past progressive shows an active action that was happening: estaba viviendo en Madrid temporalmente, estaba yendo al gimnasio cuando me llamó, estaban arreglando la casa. If the sentence presents a habit, situation, or description, the simple imperfect is used. If it presents a ongoing process, to be in imperfect + gerund is used.