]Direct speech refers to reproducing words exactly as they were originally spoken . These words are put between qutation marks . For example :
The teacher says , " I have some books in my hand . "

Indirect speech refers to using a noun clause to report what someone has said . No qutation marks are used , e.g : The teacher says (that) he
has some books in his hand
ملاحظة : عندما يكون فعل النقل مضارعا" مثل
say , says يبقى زمن الفعل على ما هو حتى بعد النقل كما في المثال السابق

Note : It is preferable not to use ( that ) in the reported speech between the verbs ( tell , and say ) .

How to perform the indirect speech ?

First , we begin the sentence by : he said , declared , stated , ......etc .
Second , Transform the pronoun ( I ) to ( he ) and the pronoun ( we ) to ( they)
Third , Change the reporting verb to its suitable tense :

1- If the reporting verb is simple present , the noun clause verb becomes simple past , e.g :

The boy said , " I go to school . "
It becomes : The boy said he went to school

2- Present continuous changes to past continuous , e.g :

They said , " We are going to the theatre . "
They said ( that ) they were going to the theatre.

3- Present perfect changes to past perfect , e.g :

Peter said : " I have gone to my uncle's . "
Peter said he had gone to his uncle's .

4-Present perfect continuous changes to past perfect continuous , e.g :

Ali said , " We have been practicing all day . "
Ali said they had been practicing all day .

5- Simple past changes to past perfect , e.g :

He said , " I wrote a letter to my father . "
He said he had written a letter to his father .

6- Past continuous changes to past perfect continuous , e.g :

He said , " I was sleeping when they come . "
He said he had been sleeping when they had come

To be continued

 
Note : We don't change the tense of the direct when it refers to general statements of fact , timeless truths , habitual or everyday activities , and proverbs
e.g :
The teacher said , " A friend in need is a friend in need . "
The teacher said a friend in need is a friend in need .

Complement :
7- Past perfect = past perfect , e.g :
She said , " I had written three letters before he came . "
She said ( that ) she had written three letters before he had come.

8- Siple future changes to future in the past , e.g :
He said , " I shall beat him easily . "
He said he would beat him easily.

9- Future continuous changes to future in past continuous , e.g :
Sami said : " I shall be going to the match this afternoon . "
Sami said he would be going to the match this afternoon .

10- Future perfect changes to future in past perfect , e.g :
The girls said , " At nine o'clock we shall have gone to the theatre . "
The girls said at nine o'clock they would have gone to the theatre.

11- Future perfect continuous changes to future in past perfect continuous ,e.g:
He said , " By soon I shall have been walking for three hours."
He said by soon he would have been walking for three hours.

Note : There are some adverbs and demonstrative pronouns that must be changed when changing the sentence from direct into indirect speech , such as :

here changes to there
this changes to that
these changes to those
now changes to then , at once , just then
today changes to that day
tomorrow changes to the next day
yesterday changes to the day before , the previous day
ago changes to before

e.g : He said , " I want this bag here and these boxes as well . "
He said he wanted that bag there and those boxes as well.