10.3. Grammar. Reported Speech.
The main rule is that tenses take a ‘step-back’, if they can.
PRESENT SIMPLE becomes...... past simple
PRESENT CONTINUOUS becomes..... past continuous
PRESENT PERFECT becomes....past perfect
PAST SIMPLE becomes.....past perfect
PAST PERFECT becomes.....past perfect
WILL becomes.....would
CAN becomes....could
MUST becomes.....had to
SHOULD becomes.....should