Consider the following two sentences:
Why can I not open the door?
and
Why can not I open the door?
Which is more common? What's the subtle difference between them?
Consider the following two sentences:
Why can I not open the door?
and
Why can not I open the door?
Which is more common? What's the subtle difference between them?
The former is definitely more common; the latter sounds rather dated, and interpretations may vary depending on the different connotations that it could provoke. The second option is often found in its contracted form, though: "Why can't I open the door?".
Have a look at this question on cannot versus can't and the wh-movement it references. Note that the example in that answer is nearly identical to yours, and it opts for the former or contracted form.