The second major use of the imperfetto is to describe an action that was in progress at some point in the past. English usually expresses this with the past progressive: was doing, was reading, were eating. Italian collapses both the past progressive and the habitual past into the single imperfetto form, so a phrase like leggevo can mean either "I used to read" (habitual) or "I was reading" (ongoing). Context — and especially other clauses in the sentence — tells you which one is meant.
This page focuses on the ongoing-action use, which has a signature pattern: the imperfetto sets the scene of an action in progress, and a punctual completed event (almost always in the passato prossimo or passato remoto) interrupts or marks a moment within that backdrop.
The classic interruption pattern
The most common construction with the ongoing imperfetto is the interruption: an action was unfolding (imperfetto) when something else happened (passato prossimo). Italian uses this pattern relentlessly, and getting it right is one of the cleanest signs of an intermediate learner who has internalized the aspectual system.
The structure: [imperfetto] + quando / mentre + [passato prossimo] — or the reverse order with mentre in front.
Mentre dormivo, è suonato il telefono.
While I was sleeping, the phone rang.
Parlavo con Marco quando è arrivato Paolo.
I was talking with Marco when Paolo arrived.
Stavamo per cenare quando è andata via la luce.
We were about to have dinner when the lights went out.
Mentre cucinava, mio marito ascoltava la radio.
While he was cooking, my husband was listening to the radio.
The imperfetto is the canvas; the passato prossimo is the brushstroke that lands on it. The ongoing action sets the temporal frame; the punctual event identifies a specific moment within that frame.
Signal words for the ongoing imperfetto
A small set of conjunctions and adverbs strongly signal an ongoing past action.
| Italian | English | Typical role |
|---|---|---|
| mentre | while | introduces ongoing action |
| quando | when | introduces ongoing OR punctual action — context decides |
| in quel momento | at that moment | locates a moment within an ongoing scene |
| in quei giorni / in quegli anni | in those days / in those years | open extended period |
| intanto / nel frattempo | meanwhile | parallel ongoing action |
| già | already (in progress) | action already underway |
In quel momento pensavo a tutt'altro.
At that moment I was thinking about something completely different.
In quei giorni studiavo per gli esami e dormivo pochissimo.
In those days I was studying for exams and sleeping very little.
Quando sono entrato, lui parlava al telefono.
When I came in, he was talking on the phone.
Intanto io preparavo la cena, mentre i bambini giocavano in salotto.
Meanwhile I was preparing dinner, while the kids were playing in the living room.
Quando: a conjunction that takes either tense
Unlike mentre — which always introduces an ongoing imperfetto action — quando ("when") is neutral. It can introduce either an ongoing imperfetto or a punctual passato prossimo, and the choice is made on aspectual grounds.
| Imperfetto after quando | Passato prossimo after quando |
|---|---|
| Quando ero piccolo, abitavo a Napoli. When I was little, I lived in Naples. | Quando ho saputo la notizia, ho chiamato mio fratello. When I heard the news, I called my brother. |
| Quando piangeva, gli davo il ciuccio. When he was crying, I'd give him the pacifier. | Quando è arrivata Maria, abbiamo iniziato a mangiare. When Maria arrived, we started eating. |
The first column treats quando as introducing an open period or ongoing state. The second treats quando as marking a punctual moment. Both are correct — the tense follows the meaning.
Two simultaneous ongoing actions: both imperfetto
When two actions were unfolding in parallel — neither one interrupting the other, both stretched out together — both verbs go in the imperfetto. This is one of the cleanest tests for the ongoing use: if both actions describe in-progress backdrops that overlap in time, both stay imperfective.
Mentre io leggevo, lui scriveva.
While I was reading, he was writing. (parallel ongoing actions)
I bambini giocavano in giardino e gli adulti chiacchieravano in cucina.
The kids were playing in the garden and the adults were chatting in the kitchen.
Pioveva forte e il vento soffiava contro le finestre.
It was raining hard and the wind was blowing against the windows.
Aspettavo l'autobus mentre guardavo le notifiche sul telefono.
I was waiting for the bus while I was checking notifications on my phone.
In each of these, neither action "interrupts" the other — they coexist as parallel backdrops, and the imperfetto is the only correct tense.
Stare + gerundio: the explicit progressive
Italian also has a more explicit progressive construction — stare + gerundio — that exactly mirrors the English was doing. This is the Italian past progressive proper. It is less common than the simple imperfetto but is used when the speaker wants to emphasize that the action was unfolding right at that moment.
The structure: stare in the imperfetto (stavo, stavi, stava, stavamo, stavate, stavano) + the gerundio of the main verb.
| Subject | stare (imperfetto) |
| Translation |
|---|---|---|---|
| io | stavo | guardando | I was watching |
| tu | stavi | parlando | you were speaking |
| lui / lei | stava | leggendo | he/she was reading |
| noi | stavamo | dormendo | we were sleeping |
| voi | stavate | scrivendo | you were writing |
| loro | stavano | uscendo | they were going out |
Stavo guardando la TV quando hai chiamato.
I was watching TV right when you called.
Stavamo cenando quando sono arrivati gli ospiti.
We were having dinner when the guests arrived.
Cosa stavi facendo a quell'ora?
What were you doing at that hour?
The simple imperfetto is the default; stare + gerundio is reserved for cases where you want to insist that the action was unfolding precisely at the moment in question. Cenavo quando sono arrivati and stavo cenando quando sono arrivati both translate as "I was having dinner when they arrived," but the second version foregrounds the unfolding more sharply.
Imperfetto vs passato prossimo with duration phrases
A common decision point: when an action lasted for some duration, do you use the imperfetto (ongoing) or the passato prossimo (closed event)? The answer depends on whether the duration is closed (specific endpoints) or open (still unfolding from the speaker's perspective at that point).
| Imperfetto (open / unfolding) | Passato prossimo (closed / quantified) |
|---|---|
| Studiavo quando è venuto mio fratello. I was studying when my brother came. | Ho studiato per tre ore. I studied for three hours. |
| Aspettavo Sara da mezz'ora. I had been waiting for Sara for half an hour. | Ho aspettato Sara per mezz'ora. I waited for Sara for half an hour (and stopped). |
| Lavoravo lì da molti anni. I had been working there for many years. | Ho lavorato lì per cinque anni. I worked there for five years (and left). |
The contrast in the second row is delicate but important. Aspettavo Sara da mezz'ora (with da, "for half an hour up to that point") leaves the wait open — Sara might arrive next, or never come. Ho aspettato Sara per mezz'ora (with per, "for half an hour total") closes the box — the wait happened, ended, and is now in the past.
Aspettavo l'autobus da venti minuti quando finalmente è arrivato.
I had been waiting for the bus for twenty minutes when it finally arrived.
Ho aspettato l'autobus per venti minuti, poi sono andato a piedi.
I waited for the bus for twenty minutes, then walked.
Italian collapses what English splits
This is where the Italian system reveals its elegance. English uses three distinct constructions for past imperfective meaning:
- was doing — past progressive (I was reading)
- used to do — habitual past (I used to read)
- would do (habitual sense) — habitual past (I would read every night)
Italian collapses all three into the single imperfetto form.
Leggevo.
I was reading. / I used to read. / I would read.
Mentre leggevo, lei dormiva.
While I was reading, she was sleeping. (ongoing)
Da bambina leggevo un libro a settimana.
As a child I used to read a book a week. (habitual)
Ogni sera prima di dormire leggevo un capitolo.
Every evening before bed I would read a chapter. (habitual)
The same form leggevo covers all three meanings. Context — adverbials, surrounding clauses, signal phrases — disambiguates. This is why English speakers often feel they need to decide which "kind" of imperfetto to use; the truth is that Italian doesn't make the distinction, and the imperfetto simply means "imperfective past" without specifying further.
A subtle aspectual contrast: studiavo vs ho studiato
A frequent minimal pair illustrates the difference between ongoing and completed action:
Studiavo quando è suonato il telefono.
I was studying when the phone rang. (ongoing — the studying was unfolding)
Ho studiato e poi ho risposto al telefono.
I studied and then answered the phone. (completed — finished studying first)
Both sentences feature studying and a phone, but they describe completely different sequences of events. The imperfetto sentence places the studying and the phone-ring in simultaneous time (the ring lands while studying is unfolding); the passato prossimo sentence places them in sequential time (study, then answer). Italian forces this aspectual choice — English speakers must learn to make it deliberately.
Common mistakes
❌ Mentre ho dormito, è suonato il telefono.
Incorrect — 'mentre' requires an ongoing action, which means imperfetto, not passato prossimo.
✅ Mentre dormivo, è suonato il telefono.
Correct — mentre + imperfetto for the backdrop, passato prossimo for the punctual event.
❌ Parlavo con Marco quando Paolo arrivava.
Incorrect — the arrival is a punctual event interrupting the conversation, so it needs passato prossimo.
✅ Parlavo con Marco quando è arrivato Paolo.
Correct — ongoing imperfetto (parlavo) + punctual passato prossimo (è arrivato).
❌ Stavo guardando la TV ogni sera.
Incorrect — 'ogni sera' signals a habit, which uses simple imperfetto, not stare + gerundio.
✅ Guardavo la TV ogni sera.
Correct — habitual past = simple imperfetto.
❌ Mentre io leggevo, lui ha scritto.
Awkward — both actions are parallel ongoing backdrops; both should be imperfetto.
✅ Mentre io leggevo, lui scriveva.
Correct — parallel ongoing actions, both imperfetto.
❌ Ho aspettato l'autobus da venti minuti.
Incorrect — 'da' (still ongoing up to that point) demands the imperfetto with this aspectual reading.
✅ Aspettavo l'autobus da venti minuti.
Correct — open-ended waiting up to that moment = imperfetto.
❌ Stavo studiavo per tre ore.
Incorrect — wrong construction (you cannot have two finite past forms) and wrong aspect (a closed three-hour stretch needs passato prossimo).
✅ Ho studiato per tre ore.
Correct — closed duration = passato prossimo.
Key takeaways
The ongoing imperfetto describes actions that were in progress at some point in the past. The default form is the simple imperfetto (leggevo); the explicit progressive (stavo + gerundio) exists for emphasis but is not needed in most cases.
Three patterns to internalize:
Imperfetto + passato prossimo with quando/mentre. Mentre dormivo, è suonato il telefono. The imperfetto sets the unfolding scene; the passato prossimo lands the punctual event.
Two parallel ongoing actions: both imperfetto. Mentre io leggevo, lui scriveva. Neither interrupts the other.
Stavo + gerundio is for emphasis only. Stavo guardando la TV foregrounds the unfolding moment more sharply than guardavo la TV, but the simple form is the default.
The ongoing use is one of three core uses of the imperfetto. The other two — habitual past actions and descriptions and background — share the same imperfective logic. A single Italian sentence often layers all three uses simultaneously, and getting comfortable with that layering is what makes your Italian start sounding fluent.
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