直接引语是把别人的原话加引号照抄下来；间接引语是用自己的话转述，实际上就变成了一个宾语从句。
四种句型的转换
1.陈述句 → 用 that 引导（that 可省略）
He said, “I am busy.” → He said (that) he was busy.
2.一般疑问句 → 用 if / whether 引导，改成陈述语序
She asked, “Do you like music?” → She asked if I liked music.
3.特殊疑问句 → 用原来的疑问词引导，改成陈述语序
He asked, “Where do you live?” → He asked where I lived.
4.祈使句 → tell / ask sb (not) to do sth
He said, “Don't be late.” → He told me not to be late.
时态往后退一格（主句是过去时的时候）
一般现在时 → 一般过去时；一般过去时 → 过去完成时；
现在完成时 → 过去完成时；→；→；→
例外：客观真理不变时态。
The teacher said the earth moves around the sun.（老师说地球绕着太阳转。）
人称、时间和地点词也要变
→ / she；→；→ / her
→；→；→；→
→；→；→
口诀
一变引导二变序，三变人称时态齐；真理不变照原样，祈使句用不定式。