Study materials
Report somebody's question and it loses every sign of being a question.
"Where do you live?" he asked.
He asked where I lived.
The helper do is gone, the question mark is gone, and the word order is that of an ordinary statement. Because a report is no longer a question: it is a story about somebody asking one.
The word order goes back to normal
This is the main rule of the topic. In a report the subject stands before the verb again, and the helpers do, does and did disappear.
"What does she want?" → He asked what she wanted.
"When did they leave?" → She asked when they had left.
The tenses shift here exactly as in reported statements: one step back.
The question word stays
If the original had what, where, when, why or how, that word becomes the link in the report. Nothing needs to be added.
He asked why I was late.
She wanted to know how it worked.
If there was no question word
Yes-no questions have no link word of their own, so one is added: if or whether. Both are equally correct; whether sounds slightly more formal.
"Are you ready?" → She asked if I was ready.
"Did he call?" → They asked whether he had called.
Requests and orders
Here a quite different and much simpler structure takes over. A request is reported with ask plus the person plus an infinitive with to. An order works the same way with tell.
"Please wait here." → She asked me to wait there.
"Sit down." → He told us to sit down.
A negative request puts not in front of the to.
"Don't touch it." → He told me not to touch it.
The mistakes everyone makes
The first is keeping question word order.
He asked where did I live. → He asked where I lived.
The second is losing if in a question with no question word.
She asked I was ready. → She asked if I was ready.
The third is reporting a request with that.
She asked that I wait. → She asked me to wait.
All three are caught by one look at the sentence. Could you put a full stop at the end and read it as a calm statement? If so, the word order is right.
Try it right now
Recall two questions you were asked today: one with a question word, one a yes-no question.
Report both in English, then add one request with asked me to. Check that no did is left anywhere.