 过去进行时 不变

(三)时间状语、地点状语及某些对比性的指示代词和动词变化

 Now...then

 Today...that day

 Yesterday...the day before

 last week(month)..the week(month)before

 Tomorrow...the next(following)day

 next year...the year before

 two days ago...two days before

 This...that

 These...those

 Here...there

 Come...go

 Bring...take

(四) 从句时态无须改变的情况

 He always says, "I am tired out. "

 He always says that he is tired out.

 He will say, "I'll try my best to help you. "

 He will say that he will try his best to help me.

 He said, "I went to college in 1994. "

 He told us that he went to college in 1994.

 He said，"When I was a child, I usually played football after school. "

 He said that when he was a child, he usually played football after school.

 Our teacher said to us, "Light travels faster than sound. "

 Our teacher told us that light travels faster than sound.

 He said，"Practice makes perfect. "

 He said that practice makes perfect.

 He said, "She must be a teacher. "

 He said that she must be a teacher.

 The doctor said, "You'd better drink plenty of water. "

 The doctor said I'd better drink plenty of water.

Conclusion

 1. 当主句的谓语动词是一般现在时的时候

 2. 当主句的谓语动词是将来时的时候

 3. 当直接引语部分带有具体的过去时间状语时

 4. 当直接引语中有以when, while引导的从句，表示过去的时间时

 5. 当直接引语是客观真理或自然现象时

 6. 当引语是谚语、格言时

 7. 当直接引语中有情态动词should, would, could, had better, would rather, might, must, ought to, used to, need时

(五)直接引语变成间接引语，句子结构的变化

 陈述句

 He said, "I have been to the Great Wall. "

 He said to us that he had been to the Great Wall.