The accepted (and highly upvoted) answer to the question in the question [What’s the rule for using “who” and “whom” correctly?](https://english.stackexchange.com/questions/56/what-s-the-rule-for-using-who-and-whom-correctly) states that the easiest way to find out whether to use *who* or *whom* is to try with *he/him* and see which fits.

But that doesn’t seem to fit very well in this case:

> 
> 1. **Who** will it be?
> 2. **Whom** will it be?
> 
> 
> 

If I replace with *he/him* there, it becomes:

> 
> 3. Will it be **he**?
> 4. Will it be **him**?
> 
> 
> 

– and I don’t know which of these is right, either. Is it really true that you can always associate *who* with *he* and *whom* with *him*? Or does that not always work? And which out of 3 and 4 **is** correct?