Present Simple → Past Simple: "I work" → He said he worked.
Present Continuous → Past Continuous: "I am working" → He said he was working.
Present Perfect → Past Perfect: "I have worked" → He said he had worked.
Past Simple → Past Perfect: "I worked" → He said he had worked.
Future (will) → Would: "I will work" → He said he would work.
can → could: "I can swim" → He said he could swim.
may → might: "I may come" → He said he might come.
must → had to: "I must go" → He said he had to go.
2. Pronoun Changes
I → he/she
you → I/he/she/they
we → they
my → his/her
your → my/his/her/their
our → their
3. Time and Place Changes
now → then
today → that day
tonight → that night
yesterday → the day before
tomorrow → the next day
here → there
this → that
these → those