Reported Speech comes in two forms: direct quotes and indirect quotes. For direct quotes, the original speaker's exact words are used within quotation marks. For indirect quotes, the original words are paraphrased and no quotation marks are used.
George said, "I cannot tell a lie."
George said that he couldn't tell a lie.
Molly asked, "May I have a cookie?"
Molly asked if she could have a cookie.
In conversation, the past tense is normally used when reporting what someone else has said. However, present tense is also possible.
Grandpa said (that) he would come to visit us next week.
Calvin told me that he was from North Carolina.
I heard that you were a computer programmer.
Maria says you come from Florida.
In formal situations, both present and past tense are widely used.
Dr. Sownso states that . . .
The research shows that . . .
Mr. Tracy concluded (that) . . .
In their study, Meyers and Blake claim . . .
According to Dr. Bill, . . .