The Imperfect Tense
If the aorist tense is for swift, completed actions in the past, its counterpart is the imperfect (imperfekt). It is used exclusively with imperfective verbs to describe continuous, ongoing, or habitual actions in the past.
Like the aorist, the imperfect is rarely spoken today. You will encounter it in older literature, fairy tales, and memoirs to set a nostalgic or descriptive scene. For the third-person plural ("they"), you will frequently see the ending -ahu:
The Verb "Biti" (To Be)
The verb biti has a distinct and very common imperfect form that you will see constantly in historical texts: bijaše (he/she/it was) and bijahu (they were).
For the third-person singular ("he/she/it"), the defining ending is -aše. Notice how it is used here alongside bijaše to describe an ongoing state:
Because of historical sound changes, the final consonant of a verb's root sometimes shifts before the imperfect endings. For example, z might become ž (dolaziti → dolažahu), or sl might become šlj (misliti → mišljaše). If you look for the imperfect ending and sound out the root, you can usually recognize the original verb.
Setting the Scene
Authors use the imperfect to paint a lingering, continuous picture of the past. As you read these final examples, note how the -aše (singular) and -ahu (plural) endings freeze the characters in time, describing what they were doing in the background.
