We can report:

• statements (with tell and say)
• questions (with ask)
• commands, requests, suggestions (with admit, claim, promise, explain, deny, insist, suggest)

Direct speech is the exact words someone said. We use quotation marks in Direct speech.

• "I'll go to London," she said.

Reported speech is the exact meaning of what soemone said but not the exact words. We do not use quotation marks in Reported speech.

• She said she would go to London.

say: we use it in both Direct and Reported speech, but in Reported speech we use say when it is not followed by the person the words were spoken to.

said + (what was said) - without a direct object 

• Direct speech: She said to me, " I am very tired."
• Reported speech: She said she was very tired.

tell: we use tell in Reported speech when it is followed by the person the words were spoken to.

told + a person + (what was said) - when there is a direct object

Reported statements

1. To report statements we use an reporting verb (say, tell, advise, explain, promise, admit, claim, confirm, deny, insist, remind)
2. Pronuns and possessive adjectives change acording to the meaning.

• Direct speech: He sad, "I can't fix it by myself."
• Reported speech: He said he couldn't fix it himself.
• Direct speech: "This is my book," he said.
• Reported speech: He said that was his book.

3. Certain words change as follows:

1. Direct speech: this/these,  here,  come
2. Reported speech: that/those,  there,  go

Some important facts to have in mind:

Modal verbs that change:

• can changes to could
• will changes to would
• may changes to might

Modal verbs that do not change:

would, could, might, should, ought to, mustn't

Be aware of must: 

Must stays the same or changes to had to.

"You must work harder." 

She told me I must work harder.

She told me I had to work harder.

When the reporting verb is in the Past Tense the verb tenses change as follows:

• Present Simple to Past Simple

"I can't remember his name," she said.

She said she couldn't remember his name.

• Present Continous to Past Continous

"I'm saving up." He said he was saving up.

• Present Perfect to Past Perfect

"I've bought you some flowers," she said.

She said she had bought me some flowers.                                  

• Past Simple to Past Perfect

"He lost all the money," she said.

She said that he had lost all the money

• Future (will+infinitive) to Conditional (would+infinitive)

"I'll see you later," he said.

He said he would see me later.

Hint: the verb in the reported speech usually 'goes back' one tense into the past

Exception: Past Perfect and Past Continuous stay the same: had played and was playing

There are no changes in verb tenses when the reporting verb is in one of the following tenses:

• Present
• Future
• Present Perfect

• or when the sentence expresses general truths, permanent states and conditios

• "Water turns into ice," he said. 
• He said water turns into ice. (permanent truth)

• or the speaker reports something immediateley after it was said: 
• "I will call you back," he said.
• He said he will call you back. (immediate reporting)

Reported questions

For Reported questions the affirmative word order (subject + verb) is used and there is no question mark.

a) ask + wh- word + object when the direct question begins with what, why, who, where etc

b) ask + if/whether + object when the direct question begins with and auxiliary verb like do, have, can etc

We use Indirect questions to ask for information/advice.

• I wonder whether to phone her.
• Do you know what time it is?

If the Indirect question starts with I wonder ... or I doubt..., then the question mark is omitted.

We use Reported questions to report someone else's questions, suggestions, offers or requests.

• He asked me whether he should phone her.
• He asked me what time it was.

Question words like what, who, where etc or whether can be followed by an infinitive in the reported sentence.

• He asked me where to put it.

• Construction in Reported commands, warnings, requests and advice: Subject+verb+object+infinitive with to

1. "Shut up">He told me to shut up.
2. "Don't go">She advised us not to go.

• Agree, invite, offer, promise, remind as reporting verbs: Subject+verb+(object)+infinitive with to

1. "Please come with us.">They invited me to go with them.
2. "I promise I'll pay."> I promised to pay.

• Add, admit, agree, claim, comment, deny, explain, insist, suggest can also be used as reporting verbs: Subject+verb+that clause

1. "I love him."> She admitted that she loved him.