老师原话："I am busy." 你转述给别人：Tom said that he was busy. 这就是直接引语变间接引语。
三步走
第一步：去引号，加 that（宾语从句）
Tom said, "I am busy." → Tom said that I am busy.
第二步：人称跟着说话人调
从句里的 I 指 Tom，改成 he：
→ Tom said that he am busy.
第三步：时态退一档
主句 said 是过去时，从句退一档：am → was
→ Tom said that he was busy.
时态后退对照表
- am/is → was
- are → were
- do/does → did
- will → would
- can → could
- have → had
时间地点词也要换
- now → then
- today → that day
- yesterday → the day before
- tomorrow → the next day
- here → there
- this → that
疑问句变间接引语
原问句语序要改回陈述语序：
- He asked, "Where do you live?"
- He asked where I lived.
祈使句变间接引语
用 tell / ask sb to do：
- He said, "Open the door."
- He told me to open the door.
口诀：去引号加 that，人称跟着说话人改；时态退一档，明昨 here now 全换位。
