Present perfect with haben
The German perfect tense implies that a present tense verb is describing a past event, such as "I have cleaned the bathroom three times this week". You will need to conjugate the helping verb haben (to have) when using the perfect tense and also add the prefix ge- to the conjugated verb.
Examples:
I said that: ich habe das gesagt (sagen: to say)
We worked hard: wir haben schwer gearbeitet (arbeiten: to work)
He played well: er hat gut gespielt (spielen: to play)
She did not know that: sie hat das nicht gewusst (wissen: to know or realize)