Pretérito Imperfeito

The pretérito imperfeito (imperfect past) expresses ongoing, habitual, or repeated actions in the past, often translated as "used to" or "was doing" in English. This tense paints the background of a story, describing what was happening when another action occurred: "Eu dormia quando ele chegou" (I was sleeping when he arrived). Formation is highly regular: -AR verbs use -ava, -avas, -ava, -ávamos, -avam, while -ER/-IR verbs use -ia, -ias, -ia, -íamos, -iam. Only four verbs are irregular in the imperfeito (ser, ter, vir, pôr), making this one of the most predictable tenses to conjugate once you master the patterns.