Modal verbs form the present perfect and the past perfect tenses with the auxiliary verb haben + infinitive, instead of the past participle (Partizip II).
| Examples |
| Ich habe sofort nach Haus gehen müssen. |
However, when modal verbs function as full verbs (i.e not connected to an infinitive), they form the present perfect and the past perfect with the past participle (Partizip II).
| Examples |
| Ich habe sofort nach Haus gemusst. |