Basic Tense Chart
The tenses generally move backwards in this way (the tense on the left changes to the tense on the right).
Other verb forms
Other verb forms also sometimes change:
Things are slightly more complicated with imperatives.
Time and place references
Time and place references often have to change:
"I went to the theatre last night"
→ He said he had gone to the theatre the night before.
"I'm having a party next weekend"
→ He said he was having a party the next weekend.
"I'm staying here until next week"
→ He said he was staying there until the following week.
"I came over from London 3 years ago"
→ He said he had come over from London 3 years before.
You also need to be careful with personal pronouns. They need to be changed according to the situation. You need to know the context. For example, there is possible confusion when you try to change reported speech to direct speech:
She said she'd been waiting for hours. (Is she one person or two different people?)
I told them they would have to ask permission. (Are we talking about two groups of people or only one?)