when/if you're finished ?

[ph2004]

Is it : "Let me know when you're finished" or is it "let me know if you're finished" ? Or are both possible and have a different meaning ?

[sarat_106]

Is it : "Let me know when you're finished" or is it "let me know if you're finished" ? Or are both possible and have a different meaning ?

It is the 1st one because your intention is to express a single completed action(time related); as:
If you are working in the garden, please let me know when you're finished.
Let me know when you're finished having lunch with me and I will arrange for your transport
You can not use the second one here.
Take the example of a more practical use:
I am now working on the complex problem of global worming on earth that will soon be released to the media after editing. Any idea or suggestions at this stage are always welcomed.
This is burning topic fit for making more and more people aware of. Let me know when you're finished refining it

[svartnik]

I do not have any problem with the 'if' version.

'If' may mean when/whenever: If I do not understand, I ask questions.

Let me know if you are ready.

[bhaisahab]

Is it : "Let me know when you're finished" or is it "let me know if you're finished" ? Or are both possible and have a different meaning ?

"Let me know when you've (you have) finished" and "Let me know if you've (you have) finished" are both possible. They mean, let me know when/if you have finished (that job/what you are doing etc.) It is the thing that you are doing that will be finished, not you (hopefully).

[greegorush]

Thanks bhaisahab for correcting him . I was wondered that such a structure could have been possible.

[svartnik]

Thanks bhaisahab for correcting him.

I have always thought Sarat is a she. Sarah, Sarat -- similar.

http://www.anamezing.com/namedetail-SARAT_8173.html

[ph2004]

"Let me know when you've (you have) finished" and "Let me know if you've (you have) finished" are both possible. They mean, let me know when/if you have finished (that job/what you are doing etc.) It is the thing that you are doing that will be finished, not you (hopefully).

I thought both : "are finished" and "have finished" were correct ?

[bhaisahab]

I thought both : "are finished" and "have finished" were correct ?

Not where I come from.

[Raymott]

I thought both : "are finished" and "have finished" were correct ?

They are where I come from.
Have you finished? = Are you finished?
BUT
You can't generally use them interchangeably.
Have you finished your breakfast?
Are you finished with your breakfast?

[konungursvia]

They are where I come from.
Have you finished? = Are you finished?
BUT
You can't generally use them interchangeably.
Have you finished your breakfast?
Are you finished with your breakfast?

Same here, they're equally natural in our English.