know/ know of

[jasveron]

Would you let me know of your decision by this Friday?
or
Would you let me know your decision by this Friday?

When should I use "know of" and when just "know"?

 

[bhaisahab]

Would you let me know of your decision by this Friday?
or
Would you let me know your decision by this Friday?

When should I use "know of" and when just "know"?

Both sentences mean the same, "of" is not necessary.

 

[jasveron]

Thanks for answering. So both sentences are correct?
It seems to me that using "of" makes the sentence more formal, no?

 

[bhaisahab]

Thanks for answering. So both sentences are correct?
It seems to me that using "of" makes the sentence more formal, no?

Yes, you could see it that way.