The monster says that he will kill Elizabeth on her wedding day. The monster ends up killing Elizabeth before her wedding. This is ironic because you did not expect this to happen.
The monster escape's from Victor and kills his brother. Victor gets really angry. This is external conflict because it happened outside of a characters head.
Victor makes a monster come to life through lightning. He feels uneasy while doing this and tries to give his plan a second thought. This foreshadows how he is forced against his will to make another monster by his creation.