Simple Present
He said '' I will visit my parents tomorrow''
He said he would visit his parents the next day.
''I will be back''
He said he would be back.
''I can do everything I want''
He said he could do everything he wanted.
''Are you leaving now?''
He asked if I was / We were leaving at that moment
She said you had to do the things you thought you couldn't do.
''What are you doing here?''
''I am trying to understand English grammar''
He asked (me) what I was doing there. I answered that / told him that I was trying to understand English grammar.
''You mustn't cheat during your test''
The teacher said we mustn't cheat during our test.