"my friend his book" or "my friend's book"?

Someone I know says, e.g. "my friend his book" instead of "my friends book" or "the book of my friend", he stubbornly believes that the form with his/

Someone I know says, e.g. "my friend his book" instead of "my friend's book" or "the book of my friend", he stubbornly believes that the form with his/her is correct, but I can not find an answer or explanation on the internet to this. I learnt that the "long form" of "my friend's book", for example, is "the book of my friend", and I never heard the his/her story, alas it sounds very wrong to me. Can anyone explain what exactly is the right form and if the his/her is used in the english language in that context?

or:Someone I know says, e.g. \"my friend his book\" instead of \"my friend's book\" or \"the book of my friend\

or:my friend's bookTheFrenchKid

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