a.When he comes to my house tomorrow, I will be writing a letter.
b.When he comes to my house tomorrow, I will write a letter.
Which of those sentences is correct? Or are both sentences right?If so, what's the difference?
By the way, in the structure using 'will do' to indicate the general future tense, can continuous verbs be used with phrases that denote a specific point in time? What is the semantic implication? Does it indicate that the continuous action begins at that point in time?
thanks!