Connect the tenses and the verbs in Direct speech and in Reported speech

When we change Direct Speech into Reported speech, there is usually a back Tense change. For example, "It is hot outside" in Direct speech becomes "He said that it was hot outside" in Reported Speech.

Should / might / could / mustn't / ought to / would are not changed. For example, "I could understand it" in Direct Speech is "He said that he could understand it" in Reported Speech.

"You should do it" in Direct Speech is "He said that I should do it" in Reported Speech.

Present Simple	would
may	Past Continuous
should	had to
Present Continuous	might
Past Simple / Present Perfect	Past Simple
can	Past Perfect
Future Simple	is not changed
must	could