What is the Perfekt?
In spoken language, you use the Perfekt for almost every past action. It doesn't matter whether the action was completed or not. In books, texts and reports, the Präteritum is preferred.
To form the Perfekt you need two things: an auxiliary verb (sein or haben) and the past participle (Partizip II).
In spoken German, the Präteritum can quickly sound written or stiff. When in doubt: in conversation, the Perfekt is almost always the right choice.
Perfekt with sein or haben?
Perfekt with sein
Verbs describing a change of place or a change of state use sein as the auxiliary. You also form the Perfekt with sein for: passieren, bleiben, geschehen, sein, werden, gelingen.
Perfekt with haben
All other verbs form the Perfekt with haben. This also applies to verbs with an accusative object, even when they describe a change of place.
"Er ist mit dem Auto gefahren" (movement) vs. "Er hat das Auto gefahren" (the car as object). With an accusative object, always haben.
Conjugation in the Perfekt
The auxiliary verb (sein or haben) is conjugated, the past participle stays unchanged.
Word order in the Perfekt
The auxiliary verb stands in position 2, the past participle goes at the end of the sentence.
Exercises
Three short tasks: multiple choice, fill in the auxiliary, form the past participle.
haben or sein?
Pick the correct auxiliary for the Perfekt.
Form the Perfekt: type the auxiliary
Complete with the correct form of haben or sein.
Write sentences in the Perfekt
Type the past participle of the verb in parentheses.