当你转述别人说过的话时，英语通常会把动词的时态往过去推一格。这叫时态后移（backshift），是B1水平最实用的语法结构之一：考试、写信、日常转述里都少不了它。
基本的时态后移
"I am tired," she said. → She said she was tired.
"We finished it," he said. → He said they had finished it.
| 直接引语 | 间接引语 |
|---|---|
| 一般现在时 | 一般过去时 |
| 现在进行时 | 过去进行时 |
| 一般过去时 | 过去完成时 |
| 现在完成时 | 过去完成时 |
| will | would |
| can | could |
| must / have to | had to |
| may | might |
过去完成时不会再往前推——它已经是过去时态里最靠前的一格了。could、should、might、would和ought to也不会改变：它们本来就没有更「过去」的形式。
"You should call him." → She said I should call him.
还有哪些内容会变
那些与说话人「此时此地」绑定的词，也会跟着发生变化：
- I / my → he / his，she / her
- here → there
- this → that
- today → that day；tomorrow → the next day；yesterday → the day before
- now → then
"I'll call you tomorrow," he said. → He said he would call me the next day.
什么时候不需要时态后移
如果说过的话现在依然成立，时态后移就不是必须的，往往也会被省略：
"Water boils at 100°C." → She said water boils at 100°C. ✅
"I live in Prague." → He said he lives in Prague. ✅（他现在确实还住在那里）
如果引导动词本身就是现在时（says、tells me），那就什么都不用变：
He says he is busy.
时态后移真正传达的是距离，而不是时间。 后移的时态悄悄地把这句话标记为「转述来的」；保留原本的现在时，则表示你自己也认同这个说法。
间接疑问句
有两处要变：单词顺序恢复成陈述句的正常语序，do/does/did消失。
"Where do you live?" → She asked where I lived.（不是where did I live）
"Are you coming?" → He asked whether/if I was coming.
没有疑问词的问句需要用if或whether引导。而且不再有问号。
请求和命令
用to + 动词原形：
"Please wait." → She asked me to wait.
"Don't touch it." → He told me not to touch it.
Say和tell
Tell后面必须接人，say则不需要。
❌ He said me he was late. ✅ He told me he was late. / He said he was late.
两者后面的that都可以省略：He said (that) he was late. 省略之后听起来更口语化。
更精确的引导动词
Say和tell在任何场合都用得上，但一个更精确的动词能传达出这句话的用意，而不只是内容——这正是书面转述读起来更自然的原因。
| 动词 | 结构 | 例句 |
|---|---|---|
| explain | that… | She explained that the system was down. |
| admit | -ing / that… | He admitted making a mistake. |
| suggest | -ing / that… | She suggested waiting a week. |
| offer | to + 动词 | He offered to help. |
| refuse | to + 动词 | She refused to sign. |
| promise | to + 动词 | They promised to call back. |
| warn | somebody (not) to… | He warned us not to be late. |
| complain | that… | She complained that it was too slow. |
| deny | -ing | He denied seeing the email. |
比较一下 He said he wouldn't sign it 和 He refused to sign it——后者更短，传达的信息却更多。
转述一条消息
A: Did you speak to Dana?
B: I did. She said the report wasn't ready and asked if we could move the meeting.
A: Did she say when she'd have it?
B: She promised to send it by Thursday, but she warned me not to count on the morning.
整段对话里都有时态后移，间接疑问句没有使用倒装，还有两个精确的引导动词，每一个都替代了一整句话的内容。
自测
下面的测验涉及时态后移、间接疑问句，以及say和tell的区别。