Filipino is a changing language that poses several challenges. The study was done to overcome the time needed to construct a corpus with it syntactic structure, treebank, as a part of the project where the researchers’ part is for Filipino Language Treebank. This project is, Open Collaboration for Developing and Using Asian Language Treebank (ALT). The objective of this study is to parse Tagalog text and determine grammar rules and part-of-speech tags using a Probabilistic Context-free Grammar. The model was trained and tested using the Asian Language Treebank Filipino dataset which includes Filipino sentences and their grammar rules. The system achieved 86.43% f-measure score in parsing the grammar rules and part-of-speech tags of Filipino sentences. The model can reliably be used to automatically create treebanks for Filipino sentence grammar.