Auxiliary verbs are used in combination with other verbs to form tenses, moods, or voices.
The three main auxiliary verbs in German are sein (to be), haben (to have), and werden (to become).
These verbs help form compound tenses such as the present perfect, past perfect, and future tenses.
Examples
Ich habe das Buch gelesen.
I have read the book.
Sie ist nach Hause gegangen.
She has gone home.
Wir werden Deutsch lernen.
We will learn German.