How to form the Partizip II (Past Participle)? + Sein or haben?

 Sein or Haben?

• Sein:
• Intrasitive verbs of movement: 
• gehen – to go, to walk
• laufen – to run
• fahren – to drive, to go (by vehicle)
• fallen – to fall
• fliegen – to fly
• kommen – to come
• reisen – to travel
• stolpern – to stumble
• stürzen – to fall, to plunge
• Instrasitive verbs that express a change of state: 
• aufwachen / erwachen – to wake up
• einschlafen – to fall asleep
• gefrieren – to freeze
• tauten – to thaw, to melt
• sterben – to die
• zerfallen – to decay, to disintegrate
• the following verbs: 
• bleiben – to stay, to remain
• geschehen – to happen, to occur
• gelingen – to succeed
• misslingen – to fail
• sein – to be
• werden – to become
• Haben: the rest of the verbs.

How is the Partizip II (Past Participle) formed?

• Weak verbs (schwache Verben) are regular verbs  = ge  + verb stem + t  
• lernen → gelernt (learn → learnt/learned)
• Irregular verbs 
• Strong verbs (starke Verben) are irregular verbs = ge + verb stem + en 
• sehen → gesehen (see → seen)
• Mixed verbs (gemischte Verben) are irregular verbs whose conjugation is a mix of strong and weak verbs = ge + verb stem + t 
• haben → gehabt  (have → had)

Tips

• If the German verb has an English cognate that is irregular, then the German verb is usually strong or mixed. (speak - sprechen). If the German verb has an English cognate that is regular, then, the German verb is likely regular (live - lebte). This rule is NOT failsafe! Exception: help - helfen
• The Partizip of  separable verbs, we add ge- between the prefix and the verb. (abholen →  abgeholt). The Partizip II of non-separable verbs is not formed with ge-. (bezahlen →  bezahlt)
• Verbs of movement like joggen (to jog), klettern (to climb), schwimmen (to swim), tauchen (to dive) when the focus is on a change of place; if not, we can use both sein and haben. Except for the verb tanzen (not focused on a change of place) is conjugated with only haben.

Exceptions

• Many strong and mixed verbs change their word stems in the past participle.
• gehen → gegangen (go → gone) 
• bringen → gebracht (bring → brought)
• We add an -et to weak/mixed verbs when the word stem ends in d/t.
• warten → gewartet (wait → waited)
• Verbs that end in -ieren form their past participle without ge.
• studieren → studiert (study → studied)
• Inseparable verbs form the past participle without ge.
• verstehen → verstanden (understand → understood)
• For separable verbs, the ge comes after the prefix.
• ankommen → angekommen (arrive → arrived)