Direct: The Father said, ‘Son, did I not ask you to study hard?’
Indirect: The father enquired of his son if he had not asked him to study hard.
Direct: My father said to me, ‘Where were you last night?’
Indirect: My father demanded of me where I had been the previous night.
Direct: She said, ‘Friend, will you wait for a moment?’
Indirect: She asked her friend if she would wait for a moment.

Interrogative sentences beginning with a question word

When a question begins with a question word such as what, who, whom, when, where, why, how etc., the same word is used to introduce the question in the indirect speech. In other words, the question word becomes the joining word instead of that, if or whether.

Direct: Viola said to Rosalind, ‘Where are you going?’
Indirect: Viola asked Rosalind where she was going.
Direct: The teacher asked the new comer, ‘What is your name?’
Indirect: The teacher asked the new comer what his name was.
Direct: The wolf said to the lamps, ‘Why are you all so sad?’
Indirect: The wolf asked the lamps why they were all so sad.
Direct: The mother said to her daughter, ‘Dear, how have you fared in the examination?’
Indirect: The mother asked her daughter lovingly how she had fared in the examination.
Direct: The shopkeeper said to me, ‘Which bag do you want?’
Indirect: The shopkeeper asked me which bag I wanted.
Direct: She said to him, ‘Why are you disturbing me?’
Indirect: She asked him why he was disturbing her.
Direct: I said to the boys, ‘Who teaches you English?’
Indirect: I asked the boys who taught them English.
Direct: John said to Mary, ‘What are you doing?’
Indirect: John asked Mary what she was doing.
Direct: The old man said to himself, ‘Why did I come here?’
Indirect: The old man asked himself why he had come there.

Notes:

In some sentences the object may be understood from the context and not expressed in the sentence. In such cases the object has to be supplied in the indirect speech.

Direct: He said, ‘What do you want?’
Indirect: He asked me what I wanted.

Here the object me is understood from the context.