过去将来时态的问题,如下……过去将来时的结构是：would+动词原形或was/ were going to+动词原形 那

过去将来时态的问题,如下……
过去将来时的结构是：
would+动词原形或was/ were going to+动词原形
那句中的其他动词都要用过去式吗?
比如：
He believed that everyoneshould try to be respectful to others.
Nobody knew what would happen after a hundred years.
believed和knew这两个动词都是过去式.
是不是除了那个助动词后面的是原形,其他的动词都是过去式?