Simple Present/Simple Past

Backshift of tenses

from

to

Simple Present

Simple Past

Simple Past

Past Perfect

Present Perfect

Past Perfect

will

would

Progressive forms

am/are/is

was/were

was/were

had been

has been

had been

Backshift of tenses

from

to

Peter: "I work in the garden."

Peter said that he worked in the garden.

Peter: "I worked in the garden."

Peter said that he had worked in the garden.

Peter: "I have worked in the garden."

Peter: "I had worked in the garden."

Peter: "I will work in the garden."

Peter said that he would work in the garden.

Peter: "I can work in the garden."

Peter said that he could work in the garden.

Peter: "I may work in the garden."

Peter said that he might work in the garden.

Peter: "I would work in the garden." 
(could, might, should, ought to)

Peter said that he would work in the garden.
(could, might, should, ought to)

Progressive forms

Peter: "I'm working in the garden."

Peter said that he was working in the garden.

Peter: "I was working in the garden."

Peter said that he had been working in the garden.

Peter: "I have been working in the garden."

Peter: "I had been working in the garden."

this (evening)

that (evening)

today/this day

that day

these (days)

those (days)

now

then

(a week) ago

(a week) before

last weekend

the weekend before / the previous weekend

here

there

next (week)

the following (week)

tomorrow

the next/following day