我舉例子好了
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：主句的謂語動詞可直接用引語中的said,也可用told來代替,注意,可以說said that,said to sb.that,told sb.that,不可直接說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.（不可說told that）
一般情況下直接引語中是什么詞,改成間接引語是也用這個詞,注意下ask sb （not）to do told sb to do之類的格式
百度百科里有好多例句和講解,