Question

He said" I write a letter." change into indirect

Answer 1

He said that he wrote a letter. remove " " and add that. He should be used instead of I and write instead of wrote.

Answer 2

Indirect speech  - He said"" I write a letter."" and in indirect speech, He said he would write a letter.

When you are dealing with a long format or style of speech, it's important to understand that the sentences are to be written in a way that the message conveyed is indirect.

For Eg: I will do it, and not I am doing it.