The Holy Qur'an claims that were it not the word of God it would have been full of contradictions. Why do then we sometimes find contradictions the Book?
There are no contradictions in the Holy Qur'an. Had you given some examples we could help clarify to you that such differences are the result of misunderstanding some aspects of the Holy Qur'an. Otherwise there is no chance of difference in the Holy Qur'an.
The Holy Qur'an has elaborated different matters repeatedly. It sometimes explains a matter in detail and sometimes it refers to something precisely. It sometimes discusses reasons and the other times it deals with consequences of a particular action. It focuses on external effects as we well as semantic ones. What we need to understand is matter of deliberation. It becomes clear that different discussions are made to elaborate the same fact. It is also possible that we consider two things as corollary to each other considering them the same fact but they elaborate different realities.
(Translated into English by Abid Mahmood)