Once again, is and are simply are two ways of saying the same thing. They are not interchangeable because one belongs to “I” and the other belongs to “he/she/it”. You are thoroughly misapplying them. You are the only person in this thread who has no idea what I am saying here.
You are correct about conjugating the verb meaning “to be”.
It is basic in the romantic languages and an early teaching in French. What little French I got, that part was easy.
Then I am the only person who knows the difference between is and am
Explain the difference between "This is my Body" and 'This is my Son"