"This is a book about him."
Translation:Bu onun hakkında bir kitap.
I will try to explain with my limited grammar: In this sentence "to be a book about him" is the predicate, the action of the sentence. And the subject is "This". To give the same meaning in Turkish, we have to translate the whole predicate " onun hakkinda bir kitap" and complement it with the subject, "bu" and the sentence becomes: "Bu onun hakkinda bir kitap".
Instead if the sentence to be translate was "This book is about him", the predicate would be "to be about him", translated it would give "onun hakkinda", and the subject would be "this book", translated it would be " bu kitap" , hence the final result would be "Bu kitap onun hakkinda". Hope it makes sense :)
I believe the confusion mostly arises from dropped words and suffixes for "to be" in Turkish. In this example the old fashioned way of writing these sentences would be "Bu onun hakkinda bir kitaptir" and the other sentence would read "Bu kitap onun hakkindadir" -dir indicating the predicate more clearly.
completely wrong, "bu" is by itself a subject, if you bring "bu" before the "kitap", then "bu kitap" becomes all together as one subject to give the meaning "This book", but we need this meaning "This is a book ...", so you should separate the "bu" from "kitap" by putting some word in between
I will remind you, modifiers always come before the things they modify in Turkish :D
"which book" -- "The book about him" "about him" = "onun hakkında"
Ergo "onun hakkında bir kitap"
"hakkında" is also a postposition (there are no prepositions in Turkish). If you wanted to say "about a book" the postposition would come after/post "a book."
So, "bir kitap hakkında"
It just takes some reprogramming of the mind to understand it. :)
I think he means that (onun hakkinda) would be the modifier of "bir kitap", as if saying "an about-himish book". And "about" is a preposition in English grammar, but in Turkish it translates to a possession expression: "onun hakkinda" = (on-un hak-ı)-n-da (-n as buffer), kind of "in (-da) the title of him (onun hakkı)". Have a look at www.turkishclass.com/forumTitle_58642 for an explanation on why the 'k' gets doubled.