Do you think she’ll have seen the doctor by four o’clock? Next month my parents will have been together for thirty years. At the end of this month, they will have been in their house for one year. Next month I will have worked for the company for six years. I think they’ll have got there by six o’clock. Won’t she have retired by the end of the year? (more common than Will she not have retired?)</pre>
Actually it makes sense, you just may have never seen this structure before and that's why you're confused. We will have read (pronounce as red) the book means that in the future there is a point where you will have finished the book (which you are reading now probably). The same pattern goes for German, but to me it's easier to understand in English.
Example of this kind of future sentence: We are late and by the time we get to the airport, the plane will have already left without us.
Hope that cleared it up a little for you.
No. It refers to an event that will be completed in the future.
If I plan to buy tickets to the theater, and then I plan to meet you at the theater, I might say that by the time you get to the theater, I will have bought the tickets. It means that buying the tickets is a future event, but when you meet me, it will be a past event.
I think the reason for so much frustration and confusion about this sentence is because there is no explanation that a future perfect sentence cannot stand alone. There must be another event that will happen after the future perfect verb takes place. Only then will the sentence and thought be understandable. https://www.grammarly.com/blog/future-perfect/