DISCLAIMER: This particular post is just a collection of stories about Davao Tagalog (personal insights of the author included). The "how-to-speak-Davao-Tagalog-101" was originally written by Mr. Ian Garcia sometime in '98-99. I do not own that part, as well as the Nay Pruneset story (I can no longer trace that particular blog written by someone named Weng).
For years, Davao has been known to be one of the most diverse cities here in the Philippines; having been tagged as a melting pot of cultures. True enough, a number of indigenous tribes settle in the mountainous region of the city and a number of people from different points of the country settle in Davao City for good. And because of that, the city has been home to numerous local languages of the Philippines - Tagalog, Cebuano, Hiligaynon, Chavacano, Ilokano, Bikolano - you name it.
If the Filipino language is a composition of all the dialects and languages in the Philippines , you might as well say that the language we speak in Davao City is the real Filipino language, and not Tagalog.