[Grammar] tense coincidence

[hotapplepie]

Hi!
I would like to ask the question of coincidence of tense.
Some sentences include past and future contents both.
And some books say that if a independent clause uses past tense,
then the after clause has to use past tense too.
It means tenses need to be coincidence.(past tense---past tense)
But some books say that determining will/would depends on whether matters have happened.
I am confused by the two different opinions.
Here are some examples below.

eg1. Yesterday he said John will/would come here tomorrow.

(Assuming that someone says this before "tomorrow",
whether will or would is correct?
Is there any difference?)

eg2. Peter intended to marry when he is/was 28.
(Assume Peter is just 25 years old now.)

eg3.What would you do if you win/won the game?
(Assume the game has not started yet.)

Thanks in advance!

 

[5jj]

Yesterday he said John will/would come here tomorrow.
Both are possible.

Peter intended to marry when he is/was 28.
The use of the past-tense form 'intended' suggests that he no longer intends this. Only 'would' works for me.

What would you do if you win/won the game?
The use of 'would' after 'if' makes this a less likely hypothetical than 'will'; this needs to be reflected in the past-tense form 'won'.

 

[hotapplepie]

Thanks for reply.

Yesterday he said John will/would come here tomorrow.
Both are possible.

Is there any difference?
Each of them in what condition?

Peter intended to marry when he is/was 28.
The use of the past-tense form 'intended' suggests that he no longer intends this. Only 'would' works for me.

Do you mean 'was' works ?
==>Peter intended to marry when he was 28. (I think no would or will here?)

Thanks again.