[Idiom] sure

[Unregistered]

Hello,

Is this ok:

-If you are not sure "OF" what will happen in the future, you use "will". (Do we need "OF" here?)

-If something is sure, you use "to be going to". (Here I need to know if we say: if it's sure or if it's FOR sure).

Thanks a lot, your help is very valuable.

 

[Raymott]

Hello,

Is this ok:

-If you are not sure "OF" what will happen in the future, you use "will". (Do we need "OF" here?)
No, you can use it, but it's not necessary.
-If something is sure, you use "to be going to". (Here I need to know if we say: if it's sure or if it's FOR sure).
No, you don't write "for sure". A better choice would be "certain".
Thanks a lot, your help is very valuable.

Your sentences are grammatical, but what they say is false.