Structures of reported questions

direct speech
reported question

She asked, "Is it better to wait?"
She asked if it was better to wait.

direct speech
reported question

He asked, "Have you been to Spain?"
He asked if I had been to Spain.

She asked me why I worked so much.

The word order in reported questions is: SUBJECT + VERB.

She asked me if it was raining.

Yes/no questions (closed questions) begin with if when they become reported questions.

She asked me if I had been to Bristol.

If the reporting verb (in this case ask) is in the past tense, the tenses used in the original sentence have to change:
I am becomes I was
I can becomes I could
I have been becomes I had been.

She asked me what I did for a living.