Will be gone and Will have been gone.

[swety]

Hi,
Please explain the difference between

When i will come, you will be gone.

When i will come you will have been gone.
I will be thankfull .

 

[Grumpy]

Hi,
Please explain the difference between

When I will come, you will be gone.

When I will come, you will have been gone.
I will be thankful[STRIKE]l[/STRIKE] .

Please note my corrections above.

"When I will come" is an old-fashioned style of expression, that is not used nowadays. "When I come" is more normal.
"When I come, you will be gone" means exactly what it says, and stands alone.
"When I come, you will have been gone" does not make sense without adding something on about how long you will have been gone, eg "When I come, you will have been gone for several days".

 

[ostap77]

But I guess I could also say "When I come , you will be gone for several days". There would not be much difference between "...will have been gone for..." and " ....will be gone for...", would be?

 

[Rover_KE]

But I guess I could also say "When I come , you will be gone for several days". No, you can't. You have guessed wrong.

Rover

 

[ostap77]

1) "I think about having a new beginning, about what I'm going to do by Christmas the traditional end of school's first semester."

2) " Here's the 20 things I'm going to do by next Tuesday."

I was trying to figure out the reason why the Future Simple was used in these two sentences instead of the Future Perfect . Could you give me an explanation?