We use reported speech to tell (= report) someone what another person says or said.
There are two ways of reporting something:
* Up-to-date reporting (we report something a short time after it was said, so we use the present form of the reporting verb;
there is no tense change)
* Off-date-reporting (we report something a long time after it was said, so we use the past form of the reporting verb;
there is tense change) - most often