Like modern French, Francien demonstrates two common tenses to describe actions in the past, one for simple and complete actions  (often called the preterite) and another for habitual actions, narration, and actions without a clearly defined beginning or end (the imperfect). These two tenses roughly correspond to the passé composé and imparfait in modern French usage.

Preterite 

fust (377) / 3rd person singular

oï (312) / 3rd person singular

Imperfect

aviiez (343) / 2nd person plural

estoit (140) / 3rd personal singular