Reported speech: modal and semi-modal changes

• If the reporting verb is in the past (eg said), we sometimes have to change modals and semi-modals.

• Could, would, should, ought to, had better and need do not change.
✓ 'I could swim when I was three,' said Lizzie. ➔ Lizzie said that she could swim when she was three.

• When we are expressing obligation, must in direct speech usually changes to had to, be to or should in reported speech.
✓'You must do what the referee tells you,' said the coach.
➔ The coach said that we had to/ were to/ should do what the referee told us.

• When we are expressing obligation, mustn't can become mustn't, be not to or shouldn't.
✓'You mustn't cheat under any circumstances!
➔We were told that we mustn't/ were not to/ shouldn't cheat under any circumstances.

• Must doesn't usually change to had to or should when we are expressing probability.
✓ 'It must have felt wonderful when they won!' said Dave.
➔ Dave said that it must have felt wonderful when