Я не спец но:
1.Jenny ironed the clothes after she cooked the lunch
2.The news already started when John turned on the TV
3.They set the table before the guests arrived
4.The kids went to bed by the time Steve came home
5.They tided the house after their guests left 
6.Sam waited until Joan finished speaking
Повторюсь, не спец))

1) After Jenny had cooked lunch, she ironed the clothes
2)The news had already started when John turned on the TV
3)They had set the table before the guests arrived
4)The kids had gone to bed by the time Steve came home.
5)After the guests had left, they tidied the house.
6) Sam waited until Joan had finished speaking.