时态变化
[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
现在完成时 —> 过去完成时
现在完成进行时 —> 过去完成进行时
一般过去时 —> 过去完成时
过去进行时 —> 过去完成进行时
过去完成时 —> 过去完成时 [无变化]
将来时 will —> 过去将来时 would

I said, ‘I'm not very happy at work.’
我说：“我工作不太开心。”
—> 
I told her I was not very happy at work.
我告诉她我工作不太开心。
I said I was not very happy at work.
我说我工作不太开心。

They said: ‘We're going home.’
他们说：“我们要回家了。”
—> 
They told us they were going home.
他们告诉我们他们要回家了。
They said they were going home.
他们说他们要回家了。

He said, ‘Jane will be late.’
他说：“简会迟到。”
—> 
He said Jane would be late.
他说简会迟到。

‘I've been working,’ she said.
“我一直在工作。”她说。
—> 
She said she had been working.
她说她一直在工作。

‘What happened to make her so angry?’ he asked.
“发生了什么让她这么生气？”他问。
happen 动词，发生
make (somebody) angry 让（某人）生气，使（某人）生气
—> 
He asked what had happened to make her so angry.*
他问发生了什么让她这么生气。
*疑问句间接引语的结尾不用问号。