When is “backshifting” optional?

Question

In reported speech, tenses are generally backshifted. If what was said is still true at the time of reporting then back shifting is optional. My question is, if someone doesn't backshift the tense knowing for a fact that the statement is no longer true, is that still acceptable?

For example, suppose John tells me today:

I am hungry.

Then two days later, I happen to tell my friend:

John said that he is hungry.

Even though I know that John is no longer hungry, I used the present simple tense (is). Is this usage correct?

Answer 1

If you know John isn't hungry, but you don't backshift the tense in the reported speech, then you've implied that something is true (namely that John is still hungry) when you know it isn't.

This isn't the forum to tell you whether that's wrong. Check to see if there's a stackexchange for tricky moral issues. Grammar rules aren't likely to help.

I find this site helpful in summarizing the rules for backshifting reported speech: https://www.englishclub.com/grammar/reported-speech-backshift.htm

Answer 2

I am answering the question posed in the title. Deadrat is right when he gives a negative answer to the question posed in the body text.

"Optional" is not a good word here, because when backshifting is optional the two options are not identical and one will probably be preferable according to what you want to communicate.

Backshifting is optional only when the report is in the past tense and one of two further conditions hold:

1) the reported speech would be in the present tense if it were quoted directly and what it refers to remains currently valid (in this case, you may put the reported speech in the present tense rather than the past: he told me the Earth orbits the Sun), or

2) the reported speech would be in the past tense if it were quoted directly and it is clear that what it refers to was in the past from the speaker's frame of reference (in this case, you may put the reported speech in the past tense rather than the past perfect: he told me he ate it the day before).

The alternatives that may also be used are he told me the Earth orbited the Sun and he told me he had eaten it the day before.

Whether in either case you should backshift depends on issues such as style, emphasis, rhythm, voice, and pace. Is current validity relevant? Well it may or may not be. If it is relevant, how relevant is it? Does it matter what your narrator thinks anyway? In the second case, is the past in the past status of what the speaker refers to sufficiently clear, given your audience? Is there a relevant difference between ate and had eaten, given how you wish to convey the speaker's character or state of mind, your desired pace, and so on?