直接引语和间接引语
1. 定义
直接引语：直接引用别人的原话，话中的内容原封不动地放在引号之中。例如：她说：“我很开心。”（“我很开心。”就是直接引语）
间接引语：把别人的话用自己的话转述出来，不用引号，在时态、人称代词、指示代词、时间状语和地点状语等方面可能会有变化。例如：她说她很开心。
2. 直接引语变间接引语的变化规则
人称变化：遵循“一主、二宾、三不变”原则。
“一主”：如果直接引语中的主语是第一人称（我、我们），变为间接引语时，要和主句的主语保持一致。例如：
直接引语：I said, "I like reading."
间接引语：I said that I liked reading.
“二宾”：如果直接引语中的主语是第二人称（你、你们），变为间接引语时，要和主句的宾语保持一致。例如：
直接引语：He said to me, "You are smart."
间接引语：He told me that I was smart.
“三不变”：如果直接引语中的主语是第三人称（他、她、它、他们等），变为间接引语时，人称一般不变。例如：
直接引语：She said, "He is a good student."
间接引语：She said that he was a good student.
时态变化：当主句的谓语动词是一般过去时，直接引语变为间接引语时，从句的时态要作相应的变化。
一般现在时→一般过去时。例如：
直接引语：She said, "I am a nurse."
间接引语：She said that she was a nurse.
现在进行时→过去进行时。例如：
直接引语：He said, "I am reading a book."
间接引语：He said that he was reading a book.
一般将来时→过去将来时。例如：
直接引语：She said, "I will go to school tomorrow."
间接引语：She said that she would go to school the next day.
现在完成时→过去完成时。例如：
直接引语：He said, "I have finished my homework."
间接引语：He said that he had finished his homework.
注意：如果直接引语是客观真理、自然现象、名言警句等，变为间接引语时，时态不变。例如：
直接引语：The teacher said, "The earth goes around the sun."
间接引语：The teacher said that the earth goes around the sun.
指示代词、时间状语和地点状语的变化
指示代词：this→that，these→those。例如：
直接引语：He said, "This book is mine."
间接引语：He said that book was his.
时间状语：now→then，today→that day，yesterday→the day before，tomorrow→the next day/the following day，next week→the next week/the following week，ago→before等。
直接引语：She said, "I saw him yesterday."
间接引语：She said that she had seen him the day before.
地点状语：here→there。例如：
直接引语：He said, "I live here."
间接引语：He said that he lived there.
3. 直接引语和间接引语的句型转换
陈述句
直接引语是陈述句，变为间接引语时，用that引导（that可省略），并且要根据上述规则进行相应变化。例如：
直接引语：She said, "I am happy."
间接引语：She said (that) she was happy.
疑问句
一般疑问句：直接引语是一般疑问句，变为间接引语时，将一般疑问句语序变为陈述句语序，用if或whether引导。例如：
直接引语：He asked, "Are you a student?"
间接引语：He asked if/whether I was a student.
特殊疑问句：直接引语是特殊疑问句，变为间接引语时，将特殊疑问句语序变为陈述句语序，保留原来的疑问词。例如：
直接引语：She asked, "What are you doing?"
间接引语：She asked what I was doing.
祈使句
直接引语是祈使句，变为间接引语时，将祈使句的动词原形变为不定式，根据语气使用ask/tell/order等动词。例如：
直接引语：The teacher said, "Sit down, please."
间接引语：The teacher asked us to sit down.
