I tend to answer the questions: "Have you finished?" with, "Yes, I �ve finished!"
"Are you finished?" with, "Yes, I �m finished!"
Regarding Questions and Short Answers: This is in line with the easily-learned rule, �Answer using the same verb as the questioner uses!�
For example:
"Do you like apples?" "Yes I do!"
"Have you a brother?" "Yes, I have!"
"Can you swim?" "Yes, I can!"
"Have you finished?" "Yes, I have!" = "I �ve finished!"
"Are you finished?" "Yes, I am!" = "I �m finished!"
I agree with others, who say that: "I �m finished!" has a sense of: "I �m done for!", "I �m whacked!", "I �m exhausted!", "I �m zonked!".
Incidentally, it �s true that, nowadays, we don �t say: "I �m arrived!", using the verb �To be � to form the Present Perfect Tense.
But, it hasn �t always been the situation. Until the change to Modern English, around about 1800, writers frequently used the verb �To be �, and not the verb �To have �.
For example: King James Bible, John 10, 10. "I am come that ye might have life!"
Jane Austin, in her novel "Emma": "So, you are come at last!".
When they start the assignment, does any student say: "Teacher, I�m started!" "I�m commenced!" "I m begun!" ?
Or, when they finish, does any student say: "Teacher, I�m ended!" "I�m concluded!" "I�m terminated!" ?
Not in my experience, they don �t!
Les Douglas