Must, Would , Should, Could, Ought to, Had Better, Might
(Can and Will are considered to have past forms wtih Could and Would respectively)
- "I could do it!"
- She said she could do it.
- "They wouldn't know what to do!"
- We said they wouldn't know what to do.
- "She had better do it today."
- They said she had better do it that day.
An option is to use the infinitive (or object + infinitive)
- "I'll help!"
- "Get out of here now!"
- They ordered us to get out of there.
- "I'll do my best."
- He promised to do his best.
In negative sentences, NOT goes before TO.
- "You shouldn't be late."
- She advised me not to be late.
- "I will not leave you!"
- He promised to not leave me.
Sometimes MODALS are not reported back, but we choose a suitable reporting verb with the infinitive.
- "Don't you dare do that!"
- She warned me not to do it.
- "I would tell him you loved him."
- He advised me to tell him I loved him.
When using Suggest do not use the infinitve TO form
- "Let's buy this one!"
- She suggested buying that one.
- NOT She suggested to buy...