Background Actions with "Mentre"
The word mentre means "while". In storytelling, you use it to set the scene or describe a background action that was happening over a period of time. Because these are ongoing past actions, mentre is followed by the imperfetto.
| while | mentre |
| While I was strolling, I was very hot. | Mentre passeggiavo, avevo molto caldo. |
You can also use mentre to describe two continuous background actions happening at the exact same time.
| The dog was afraid of the thunder while he was running on the wet grass. | Il cane aveva paura del tuono mentre correva sull'erba bagnata. |
Sudden Interruptions with "Quando"
When an ongoing activity is interrupted by a sudden, one-time event, we often use the conjunction quando (when), sometimes paired with words like improvvisamente (suddenly).
The ongoing background action remains in the imperfetto, while the sudden interrupting event takes the passato prossimo.
| We were strolling peacefully when suddenly it started to rain. | Passeggiavamo tranquilli quando improvvisamente ha iniziato a piovere. |
You can express the exact same relationship by putting mentre in front of the background action. The interrupting action in the main clause will still take the passato prossimo.
| While I was walking in the park, I fell in the mud. | Mentre camminavo nel parco, sono caduto nel fango. |
| While we were following this path, I saw a large flash of lightning. | Mentre seguivamo questo sentiero, ho visto un grande lampo. |
Sequential Events
Quando isn't only for interruptions. You can also use it to show that once one completed action finished, another event happened right after, or a new state was discovered. In these cases, the completed event immediately following quando takes the passato prossimo.
| When it stopped raining, we saw a rainbow. | Quando ha smesso di piovere, abbiamo visto un arcobaleno. |
| When I returned home, this dress was all wet. | Quando sono tornato a casa, questo vestito era tutto bagnato. |
