future in reported speech when reporting verb is in the past

Question

I have read the following sentence:

He said he will follow me to the end.

AFAIK in reported speech, the future tense is replaced with the conditional tense when the reporting verb is in the past. So the correct sentence should be "He said he would follow me to the end". I think that the sentence above is wrong, but oddly both Google Translate and Deep L translator chose the future tense too. What is the correct verb tense here?

Answer 1

Backshifting may not be necessary sometimes.

From Cambridge dictionary:

We don’t need to change the tense in indirect speech if what a person said is still true or relevant or has not happened yet. This often happens when someone talks about the future, or when someone uses the present simple, present continuous or present perfect in their original words:

He told me his brother works for an Italian company. (It is still true that his brother works for an Italian company.)

She said she’s getting married next year. (For the speakers, the time at the moment of speaking is ‘this year’.)

He said he’s finished painting the door. (He probably said it just a short time ago.)

She promised she’ll help us. (The promise applies to the future.)

Answer 2

I like to teach that the tense in a reported clause is "the targeted tense - 1".

In you example, it should be:

He said he would follow me to the end.

Let's look at the time line:

he said "it" here          [him following you]
    |                     -------------------------------------->
    V                     [
----o---------------------------o--------------------------------------->
                                ^
                                |
                               now

In the time line above, [him following you] is after (in the future compared to) [him saying it]. From that, you can make a "base sentence":

He will follow me to the end.

That's what you would say if you're in the same time spot as [he said it]. Now, take the "will" and "minus 1" it:

will - 1 = would

... and put that in your reported clause

... (that) he would follow me to the end.

My "minus 1" rule:

future/can --> modals:
will - 1 = would
can - 1 = could

present --> past:
present perfect - 1 = past perfect
present continuous - 1 = past continuous

past --> perfect:
past simple - 1 = past perfect
past perfect - 1 = past perfect (already furthest in the past)

Some examples:

"I will give you the money." --> He said he would give me the money.
"I can play the guitar" --> He said he could play the guitar.
"I have finished my work." --> He said he had finished his work.
"I'm doing the laundry." --> He said he was doing the laundry.
"I gave her the doll." --> He said he had given her the doll.
"I have made dinner." --> He said he had made dinner.

That's just a little trick I came up with at some point that works.