Order of Pronoun

[tedtmc]

Who am I speaking to?
May I know who I am (not 'am I') speaking to?

I have been asked why 'I am' is changed to 'am I' in the second sentence. Which is the grammar rule that says the order has to be reversed that way?

[5jj]

In indirect speech we do not normally use direct question word order,

The question mark in your example goes with the direct question 'May I know....', not with the indirect question.