Haben (to have) and sein (to be) are the two most important auxiliary verbs in German. They help form compound tenses like the perfect, past perfect, and future perfect. They also function as main verbs in their own right. Mastering when to use each auxiliary is crucial for correct German.

Conjugation

Both verbs are highly irregular and must be memorized. Here are their complete conjugations:

As Auxiliary Verbs: When to Use Haben

Haben is the default auxiliary verb and is used with the majority of German verbs:

Remember: If you're unsure, haben is likely the correct choice. It's used with about 85% of all German verbs.

As Auxiliary Verbs: When to Use Sein

Sein is used with specific types of intransitive verbs:

Tip: Think of sein verbs as expressing a journey or transformation - either physical movement from A to B, or a change from one state to another.

Common Movement Verbs with Sein

These verbs express movement from one place to another and always use sein as their auxiliary:

Change of State Verbs with Sein

These verbs express a change of state or condition and always use sein:

Special Verbs with Sein

These verbs always use sein as their auxiliary, even though they don't express movement or change of state:

Special Cases and Exceptions

Practice: Haben or Sein?

Choose the correct Perfekt form for each verb:

Quick Reference Flowchart

Use this flowchart to determine whether to use haben or sein as the auxiliary verb: