Reported Speech 1
We use reported speech when we are saying what other people say, think or believe.

He says he wants it.
We think you are right.
I believe he loves her.
Yesterday you said you didn't like it but now you do!
She told me he had asked her to marry him.
I told you she was ill.
We thought he was in Australia.
When we are reporting things in the present, future or present perfect we don't change the tense.

He thinks he loves her.
I'll tell her you are coming.
He has said he'll do it.
When we tell people what someone has said in the past, we generally make the tense 'more in the past'.

You look very nice. = I told him he looked very nice.
He's working in Siberia now. = She told me he was working in Siberia now.
Polly has bought a new car. = She said Polly had bought a new car.
Jo can't come for the weekend. = She said Jo couldn't come for the weekend.
Paul called and left a message. = He told me Paul had called and had left me a message.
I'll give you a hand. = He said he would give me a hand.
However, when we are reporting something that was said in the past but is still true, it is not obligatory to make the tense 'more in the past'. The choice is up to the speaker. For example:

"The train doesn't stop here."

He said the train doesn't stop here.
He said the train didn't stop here.
"I like Sarah."

She said she likes Sarah.
She said she liked Sarah.
When we are reporting what was said, we sometimes have to change other words in the sentence.

We have to change the pronoun if we are reporting what someone else said. Compare these two sentences. In each case the person actually said "I don't want to go."

I said I didn't want to go.
Bill said he didn't want to go.
We have to change words referring to 'here and now' if we are reporting what was said in a different place or time.
Compare these two sentences. In each case the person actually said "I'll be there at ten tomorrow."

(If it is later the same day) He said he would be there at ten tomorrow.
(If it is the next day) He said he would be there at ten today.
Now compare these two sentences.

(If we are in a different place) He said he would be there tomorrow at ten.
(If we are in the place he is coming to) He said he would be here at ten tomorrow.

Reported Speech 2
We also use reported speech when we are saying what other people asked or wanted to know. We do not use do or question marks in indirect questions.

"What time is it?" = He asked me what time it was.
"Why hasn't he come? = She wondered why he hadn't come.
"When will you be arriving?" = He wanted to know when we would be arriving.
"What were you doing?" = They questioned him about what he had been doing.
We use the same structure when we report answers.

"147 Oak Street." = I told him what my address was.
"I didn't have time to do it." = She explained why she hadn't done it.
"Look at this dress and bag." = She showed me what she had bought.
"Put the paper here and press this button." = He demonstrated how the scanner worked.
Yes/no questions are reported with if or whether.

Do you want a ride? = Mike asked me if I wanted a ride.
Are you coming? = They wanted to know if I was coming.
Will you be here later? = She asked me whether I would be here later.