Tense Changes in Reported Speech

When using Reported Speech we must remember about the correct changes of tenses.

from	into
a) Simple Present:	Simple Past
b) Simple Past:	Past Perfect
c) Present Perfect:
d) Past Perfect:
e) will	would
Progressive Forms
f) am / is	was
g) are	were
h) was / were	had been
i) has been
j) had been

from	into
a) Tom: "I write a letter".	Tom said (that) he wrote a letter.
b) Tom: "I wrote a letter".	Tom said (that) he had written a letter.
c) Tom: "I have written a letter".
d) Tom: "I had written a letter".
e) Tom: "I will write a letter".	Tom said (that) he would write a letter.
Progressive Forms
f) Tom: "I am writing a letter".	Tom said (that) he was writing a letter.
g) Tom: "They are writing a letter".	Tom said (that) they were writing a letter.
h) Tom: "I was writing a letter".	Tom said (that) he had been writing a letter.
i) Tom: "I have been writing a letter".
j) Tom: "I had been writing a letter".