1)should无词义,只是shall的过去形式,与动词原形构成过去将来时,只用于第一人称,例如:
I telephoned him yesterday to ask what I should do next week.
我昨天给他打电话,问他我下周干什么。
比较:
"What shall I do next week?" I asked.
"我下周干什么?"我问道。(可以说,shall变成间接引语时,变成了should。)
2) would也无词义,是will的过去形式,与动词原形构成过去将来时,用于第二、第三人称,例如:
He said he would come. 他说他要来。
比较:
"I will go," he said. 他说:"我要去那儿。"
变成间接引语,就成了:
He said he would come.
原来的will变成would,go变成了come.。