When we use reported speech to convey what someone has said, there is often a tense change. It might be said that the verb form in what is reported moves one tense back. Thus, when it comes to modal verbs:

will & can change to would & could
may & shall change to might & should

• 'Can I borrow your jumper?' - 'He asked me if he could borrow my jumper.'

• 'I'll pick you up from the station.' - 'He said he would pick us up, but he's not here!'

• 'I may be back late tonight.' - 'He admitted he might be back late.'

• 'What shall we give her as a gift?' - 'They wondered what they should/could give her.'

Note that there is no further change to past modal auxiliaries would, could, might or should when these forms appear in direct speech format:

• 'Would you help me to find her?' - 'He wondered if I would help him to find her.'

• 'We might look for her in Leeds.' - 'He suggested they might look for her in Leeds.'

must, ought to, used to, needn't

These modal auxiliary verbs, however, do not change in reported speech. Ought to is already a past tense modal (cf. should) and used to exists only in the past tense. Needn't is a strange auxiliary verb as it exists only in the negative. It is possible to change must to had to in reported speech, although this is usually not done. Compare the following:

• 'We must leave right now.' - 'They insisted they must/had to leave straightaway.'

• 'You needn't come with us.' - 'They told me I needn't go with them.'

• 'You ought to go and stay with mum.' - 'They thought I ought to go and stay with mum.'

• 'You must try not to worry.' - 'They told me I must try not to worry.'

need

When need is used as a main verb (cf want), it behaves as any other main verb when direct speech is reported:

• 'Do you need any bread from the shop?' - 'He asked me if I needed any bread.'

• 'He's fired. I don't need to see him.' - 'He told me I was fired and he didn't need to see me.'

• 'He needs my help and I must go to him.' - 'She said he needed her help and she must go to him.