Yes/no questions expect yes or no as the answer. We use if or whether to report yes/no questions.
Direct: ‘Will you do this?’
Indirect: She asked me if I would do that.
Direct: ‘Are you going to the market?’
Indirect: She asked me if I was going to the market.
Direct: Will you help me?
Indirect: She asked me whether I would help her.
Direct: Have you bought a new cellphone?
Indirect: She wondered if I had bought a new cellphone.
Reporting wh-questions
Note that there is no inversion of subject and verb when we report questions.
Direct: ‘What is the problem?’
Indirect: She asked what the problem was.
Direct: Who’s the best singer here?
Indirect: She asked me who the best singer was.
Direct: ‘When are you going on holiday?’
Indirect: She wanted to know when I was going on holiday.
Direct: ‘How do you feel today?’
Indirect: The doctor asked her how she felt. (NOT The doctor asked her how did she feel.)
However, do can be used in indirect negative questions.
Direct: ‘Why don’t you find a job?’
Indirect: She asked him why he didn’t find a job.
Compare:
Direct: Do you like ice-cream?
Indirect: She asked me if I liked ice-cream.
Direct: Don’t you like ice-cream?
Indirect: She was surprised that I didn’t like ice-cream.
Direct: Who is that pretty girl in the red frock?
Indirect: I wondered who that pretty girl in the red frock was.
Direct: How did you make this soup?
Indirect: I wondered how she had made that soup.
Direct: Which color would you like?
Indirect: She asked me which color I wanted.
Direct: Which cellphone did you buy?
Indirect: My father asked me which cellphone I had bought.