No Change in Verb Tenses in Reported Speech
The Introductory Verb is in the Present, Present Perfect or Future
Direct speech: He says, “I will come”.
Reported speech: He says that he will come.
Fact or General Truth
If the reported sentence deals with a fact or general truth, the present tense is (can be) retained.
Direct speech: Copernicus: “The planets revolve around the sun.“
Indirect speech: Copernicus stated that the planets revolve around the sun.
The reported sentence contains a time clause, the tenses of the time clause remain unchanged.
Direct speech: She said, “His parents died while he was still at school.”
Indirect speech: She said that his parents had died while he was still at school.
The Second or the Third Conditional
The verb of the sentence is in the unreal past (the second or the third conditional).
Direct speech: He said, “If I won the lottery, I would travel around the world.“
Reported speech: He said that he would travel around the world if he won the lottery.
The subjunctive stays unchanged in the subordinate clause.
Direct speech: The children said, “We wish we didn’t have to take exams.”
Reported speech: The children said they wished they didn’t have to take exams.
“Had Better”, “Could”, “Would”, “Used to”, “Should”, “Might”, “Ought to” and “Mustn’t” Remain Unchanged
Direct speech: He said, “You had better to be inside in such bad weather.“
Indirect speech: He said that I had better to be inside in such bad weather.
Direct speech: He said, “Ann might ring today.”
Reported speech: He said that Ann might ring that day.
Report Something Immediately
If the speaker reports something immediately or soon after it was said, the clause often remains as spoken.
A: What did the teacher say?
B: He said that we write our lesson carefully.