Present tenses (I am doing / I do) for the future

19.2

Tom wants you to visit him, but you are very busy. Look at your diary for the next few days and explain to him why you can't come.

Tom's diary schedule
  1. Tom: Can you come on Monday evening?
    You: Sorry, but
  2. Tom: What about Tuesday evening then?
    You: No, not Tuesday. I .
  3. Tom: And Wednesday evening?
    You:
  4. Tom: Well, are you free on Thursday?
    You: I'm afraid not.