How to express.

Few days ago I read an article about how to improve my English. So I'll do.
Reported speech.
When we report what someone said, we often need to make changes in order to maintain the meaning of the message. Most of the changes in English correspond to changes in Catalan.

Say, tell and ask are often misused. Here are the main uses. Of the three, only say can be used with direct speech. e.g. Brian said, "I'm hot".
As for reports, both say and tell can report statements, say without an indirect object, tell with an indirect object. e.g. Brian told me that he was hot. Brian say that he was hot.
Commands.
Brian told me to stand up.
Report questions.
Brian asked (me) if I was hungry.