直接引语变间接引语 中 什么时候用told 什么时候用asked 什么时候用said

我举例子好了
said：He said,“I am very sorry.” ——He said that he was very sorry.
The doctor said,“You'd better drink plenty of water.” ——The doctor said I'd better drink plenty of water.
ask：Mother asked,“Have you finished your homework before you watch TV?” ——Mother asked me whether I had finished my homework before I watched TV.
He asked me,“Will you go to the station with me to meet a friend of mine this afternoon?” ——He asked me whether I would go to the station with him to meet a friend of his that afternoon.
told：主句的谓语动词可直接用引语中的said,也可用told来代替,注意,可以说said that,said to sb.that,told sb.that,不可直接说told that,如：He said,“I'll give you an examination next Monday.”——He told us that he would give us an examination the next Monday.（不可说told that）
一般情况下直接引语中是什么词,改成间接引语是也用这个词,注意下ask sb （not）to do told sb to do之类的格式
百度百科里有好多例句和讲解,