Translation:I am reading the fifth page of this report.
Just to clarify(so please correct me):
--the '-un' on rapor is genitive, used for possession.
--the '-sı' on sayfa is the possessive suffix.
--the '-nı' on sayfası is accusative.
is there accusitive there because that is the object, that is what you are reading??
I think you're right but something is missing. Not any (direct) object is in accusative case in Turkish.
In addition there must be a 'specification' of this direct object. In this case it is 'beşinci'.
all of those suffixes have specific lessons, you need to learn how to add them together. if we had to make a lesson for each combination, we would probably have millions of lessons