I was writing a text in English to an Italian girl friend of mine whose English is very good. In the text, I asked:
Will you be coming to the staff party on Thursday?
and she replied
Yes, I'll be
I couldn't shrug and ignore it, I had to say something, so I texted back
You should've written: I'll be there :)
But she explained
Given that your question was: "Will you be coming...?" I thought that answering "I'll be" would be correct.
What do I tell her?!?
If the original question had been "Are you coming on Thursday?" or "Can you come on Thursday?" the answers:
(Yes,) I am
Yes, I can
would have been OK.
- What's the grammatical explanation, or rule, that says I'll be (or I will be) is wrong when a question begins with the auxiliary will?