The verbs sein (to be) and haben (to have) are critically important in German. They are used as main verbs, as auxiliary verbs for many tenses, as well as in many idiomatic expressions. They are conjugated as follows:
Sein: ich bin, du bist, er / sie / es ist, wir sind, ihr seid, sie / Sie sind
Haben: ich habe, du hast, er / sie / es hat, wir haben, ihr habt, sie / Sie haben
Sein, haben, and modal verbs in the simple past:
As mentioned above, the simple past forms of these verbs are used in both oral and written discourse. Example sentences:
Sein (to be), haben, (to have), können(can):