Every day when I sit down to write, I have to decide what I will write.
Student or Learner
Every single day when I sit to write, I'm to think what I will write.
I'm to think is awkward, and it is not used very much nowadays. Please tell the alternative ways to rewrite this sentence with similiar meaning.
I believe that "I'm to" (or "You've to" etc) is used more in Irish English. A friend of mine from Dublin uses things like "I've to go to work in the morning" or "I don't envy the fact that you've to make dinner for twelve people this evening".
In BrE, like MikeNewYork's AmE example, we use "I have to ...".
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.
The only context I'd use "I'm to think" would be to reflect or draw a conclusion from something.
"Well, he won't respond to my emails or return my calls, so I guess I'm to think I should leave him alone.'
"My mother told me I'm to sit and think on how it was wrong to do that. "
"Hmm, I'm not sure what I'm to think about his response."
Wear short sleeves! Support your right to bare arms!
However, the structure could be used for other verbs. I think the problem is the verb in the example and the contraction. I don't know what I am to do sounds much more natural to me.