I have at times noticed that there are disagreements in the grammar of certain brachot in Birchot haShachar. For example, the first brachah is "אשר נתן", one of the later ones is either (depending on custom) "אשר הכין" or "המכין", and the last short one is always "הנותן". From my limited knowledge of Hebrew grammar, these conjugations do not agree. I find that many read these brachot as a litany, which brings to mind the idea of grammatical agreement. If it makes any difference, my main siddurim are the Rödelheims, Koren, and Rinat Yisrael, all of which are Nusach Ashkenaz. However, I have also noticed this in assorted Edot Hamizrach and Sephard siddurim.
Why does the grammar of the different brachot not agree?