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."
However, they cannot be used with indirect questions (questions that are being reported). In this case we replace say or tell with ask.
E.g. "Caroline asked me to go shopping with her on Saturday."
Tell needs a personal object, in other words, we say who is told.
E.g. "She told me that she's going to the party."
Say isn't normally followed by a personal object.
E.g. "She said that she is going to the party."
If we do want to say who is being told something, we have to use to.
E.g. "She said to me that she is going to the party."
In the following sentences which verb is needed?
Lesson by Caroline
Did you understand today's lesson? Then write three example sentences using 'say', 'tell' and 'ask'.
Link: How to use reported speech
