When we use reported speech, we are usually talking about the past. So all the verbs usually change into a past form.

Present Simple  →  Past Simple

“I work hard”, he said.  → He said (that) he worked hard.

Present Continuous  → Past Continuous

“I am working hard”, he said.  → He said (that) he was working hard.

Present Perfect  →  Past Perfect

“I have worked hard”, he said.  → He said (that) he had worked hard.

Past Simple  →  Past Perfect or can stay the same

“I saw Jane at a party a week ago”, he said.  → He said (that) he saw (had seen) Jane at a party a week before.

Note: Past Perfect and Past Continuous usually remain the same in the reported speech.

·   We don’t always need to change the tense of the verb if you say something that is believed to be true.

Jane said “New York is bigger than London”.  → Jane said (that) New York is (or was) bigger

      than London.

·   We leave modals must, might, could, would, should, ought to unchanged in reported speech. But we normally change may to might in reported speech.

“You must work harder”, she said.  → She said (that) I must work harder.

“You may explain it better”, he said. → He said (that) I might explain it better.

·   We change time words and certain words in the following way:

Direct Speech

Reported Speech

tonight, today,

this week/month/year

that night, that day,

that week/month/year

now

at that time, at once, immediately

now that

since

yesterday,

last night/week/month/year

the day before,

the previous night/week/month/year

tomorrow,

next week/month/year

the following day/the day after,

the following/next week/month/year

two days/months/years etc. ago

two days/months/years etc. before

this/these

that/ those

here

there

come

go