英语中“直接引语”怎么变成“间接引语”如：" I'm doing my homewok now." my sister

英语中“直接引语”怎么变成“间接引语”如：" I'm doing my homewok now." my sister said to me .

引述别人的话时,一般采用两种方式：一是引用别人的原话,把它放在引号内,称为直接引语;二是用自己的话加以转述,被转述的话不放在引号内,称为间接引语.间接引语在大多数情况下是一个宾语从句.直接引语变成间接引语时,要注意以下几点：人称变化、时态变化、宾语从句要用陈述句语序等.
　　1.直接引语是陈述句,变成间接引语时,由连词that 引导.例如：
　　She said,“I am very happy to be with you.” →She said (that) she was very happy to be with me.
　　He said,“I will choose a book for my students.” →He said(that)he would choose a book for his students.
　　2.直接引语是一般疑问句时,变成间接引语,由连词whether或if 引导.例如：
　　He asked me,“Do you like watching TV?”→He asked me if/whether I liked watching TV.
　　He asked,“Are you sure your mother will come?”→He asked me whether / if I was sure my mother would come.
　　注意：大多数情况下,if和whether 在引导宾语从句时可以互换,但后紧跟or not时,一般只用whether.例如：
　　She asked me whether or not he could do the work./ She asked me whether he could do the work or not.
　　3.直接引语是特殊疑问句,变成间接引语时,由相应的连接词who,whom,what,whose,how,when,why,where 等引导.例如：
　　He asked:“Where are you to get off,John?” →He asked John where he was to get off.
　　My sister asked me,“How do you like the play?”→My sister asked me how I liked the play.
　　Tom asked me,“Who is the boy over there?”→Tom asked me,“Who was the boy over there?”
　　4.直接引语是祈使句,其间接引语由主语+动词ask(委婉语气),tell(一般语气),order (命令语气)或warn,advise等+复合宾语(名/代词+动词不定式)构成.如：
　　He said,“Please come here again tomorrow.”→He asked me to go there again the next day.
　　“Be careful with the dog.”→He warned me to be careful with the dog.
　　5.直接引语变间接引语时,如果引述动词为过去式,需注意时态的变化：如：
　　1) Betty said,“Lingling is singing in the classroom now.” 现在进行时→
　　Betty said Lingling was singing in the class room then.-过去进行时
　　2) He said,“I will go to London next week.” 一般将来时→
　　He said he would go to London next week.过去将来时
　　3) My mother said,“I have already cleaned the house.” 现在完成时→
　　My mother said she had already cleaned the house.过去完成时
　　注意:
　　1.直接引语是客观事实、普遍真理等,主句尽管是过去时态,变成间接引语时,时态仍然用一般现在时态.例如：
　　They told their son,“The earth goes round the sun.”→They told their son that the earth goes round the sun.
　　2.直接引语变间接引语时,指示代词、时间状语、地点状语、动词等要作相应的变化.如：this→that,these→those,now→then,today→that day,yesterday→the day before,last year→the year before,ago→before,here→there come→go等.例如：
　　He said,“I haven’t seen them today.” →He said that he hadn’t seen them that day.
　　但是,如果转述时对话人双方就在原来的地方,或在说话的当天,就不必改变相应的时间状语、地点状语等.总之,对这些变化不能机械理解,应根据实际情况来决定所作的变化.
　　3.间接引语一般要用陈述句的语序,即主、谓、宾的顺序.