Could you explain, please, the meaning of this sentence (under what circumstances can it be said?):
Rob will have passed the exam if he has studied enough.
Maybe, it will be easier to explain it if you compare the first example with the following one:
Rob will pass the exam if he has studied enough.
Is it correct that the first example describes possibility after the exam, but the second one – before the exam? Could you explain it more clearly, please?
If we use First Conditional for a future situation, I can't understand how "the first example describes possibility after the exam" because it means that the exam was already in the past. Is it correct to use Future Perfect in this case? I'm confused.
Best Answer
I think you're on the right track. Let's take these in the opposite order in which you presented them.
This is speaking solely of the event of Rob passing the exam. The speaker is predicting that event (passing the exam) will occur if the condition (he has studied enough) is met.
This is speaking of the state of things after an event. Without context, it sounds very bizarre. But let's add some context:
You'll see that this draws attention to some point in the future after the event. That is, the speaker predicts that at a point in the future (the start of the job), the event (passing the exam) will have occurred in the past.
You'll also notice that I changed "if he has studied enough" to ", assuming he has studied enough." That sounds more natural to me.
Here's another, somewhat different use of "will have" that you should probably know about.
The "will have" in this example is used to state a strong present assumption that the train left in the past. See also: https://www.grammaring.com/modals-to-express-assumption-will-should-ought-to