These two verbs are often confused. This is because they have the same meaning but are used in different ways.
Rules:
Say and tell can be used in both direct and indirect speech.
E.g.
Direct: "I said I'm hungry."
Indirect: "She told me she was hungry."
Direct speech and reported speech are the two ways we can say what someone has said.
Directed speech: "I am your neighbour," said James.
Reported speech: James said that he was my neighbour.
We use reported speech when we want to repeat what someone had previously said.
Let's look at the difference between direct speech and reported speech:
Direct Tomie said = 'I am tired.'