So we use backshift SOMETIMES but not always. And WHEN we use backshift, here's how it works with these common tenses and modals:
Look at the following examples. See if you can understand when and why they use backshift:
|tenses & modals
||He said, "I like coffee."
||He said (that) he likes coffee.
|He said (that) he liked coffee.
||She said, "Moo is living here with us."
||She said Moo is living there with them.
|She said Moo was living there with them.
||John said, "We bought a house last week."
||John said they had bought a house the week before.
||Ram said, "I haven't seen Avatar."
||Ram said he hadn't seen Avatar.
||Wayne said, "Were you watching TV when I called."
||Wayne asked if I had been watching TV when he called.
||Ati said, "I had never lived in Thailand before."
||Ati told us that he had never lived in Thailand before.
||She said, "Tara can't swim."
||She said Tara couldn't swim.
|She said Tara can't swim.
||He said, "Could you swim when you were three?"
||He asked me if I could swim when I was three.
||She said: "I may be late."
||She said she might be late. (and she was late)
|She said she may be late. (the time to be late has not yet arrived)
||She said, "I might come early."
||She said she might come early.
||She said, "I'll call you tomorrow."
||She said she would call me the next day.
|She said she will call me tomorrow. (tomorrow has not come)
||She said, "I wouldn't like to go."
||She said she would not like to go.
||He said: "Shall I open the door?"
||He asked if he should open the door.
||John said, "You should come here."
||John said I should go there.
||The kidnapper phoned me and said: "You must come here now."
||The kidnapper phoned me and said I had to go there then.
|Ati said, "I must find a job next year."
||Ati said he must find a job next year. (next year hasn't come yet)
||Tara said: "I have to do my homework."
||Tara said she had to do her homework.
|Tara says she has to do her homework.