I need your explanation of the difference between the following pairs of sentences:
I will arrive home by 5 pm.
I will have arrived home by 5 pm.
He will finish the essay by Friday. (= ?)
He will have finished the essay by Friday. (= emphasizes the essay will be completed)
She will cook by the time he gets home. (= she will start cooking before he gets back ?)
She will have cooked by the time he gets home. (= the meal will be ready?)
Thank you very much
***** NOT A TEACHER *****
I am not answering your questions, but I do have some information that may interest you:
One of my favorite books says:
"In Modern English the future perfect tense has been largely replaced by the simple future tense. Ordinarily a person would say, 'He will finish the work by next Saturday,' instead of 'He will have finished.' "
--Walter Kay Smart, English Grammar Review (1968).
Michael Swan's Practical English Usage (1995 edition) also reminds us that the future perfect can "predict the present."
He gives this example: "It's no use phoning -- he'll have left by now."
[My note: I think that it is accurate to say that many Americans would prefer to express that idea in an "easier" way: "No use phoning. He has probably left by now / He is probably gone by now."]